In 1987, after crashing into Frank and Harley on their way to the hospital, Alan-Michael Spaulding and Dinah Marler helped Harley give birth to Daisy. Harley gave Daisy up for adoption, and Daisy's new parents, Harry (Jim) and Connie Lemay, renamed her Susan. In 1989, Dylan Lewis, Susan's biological father, learned that he had a daughter, and he convinced Harley to reclaim their child. While Dylan and Samantha Marler worked undercover as Susan's babysitter, Harley's husband, Alan-Michael, attempted but failed, to buy Susan from the Lemays. Alan-Michael revealed Dylan's identity, and the Lemays fired Dylan and Sam. Alan-Michael kidnapped Susan to hold onto Harley, but Dylan was accused of the crime. Harley returned Susan to the Lemays, and Alan-Michael was sentenced to community service.

In March 1994, Connie Lemay revealed to Dylan that an eight-year old Susan had contracted a rare form of diabetes. She persuaded Dylan to donate part of his pancreas to Susan in a risky, but lifesaving, surgery. The Lemays were grateful when the procedure was a success, but still barred Dylan from seeing Susan. Dylan and Susan eventually reunited at Josh and Reva's second wedding in May 1999.

In late 1998, Connie Lemay died of cancer, and Susan ran away to Springfield to find Harley. Susan begged Harley and her then husband, Phillip Spaulding, not to return her to Jim, claiming that he'd hardened after Connie's death. When Jim arrived to pick Susan up, Harley convinced him to stay in Springfield for the holidays. Susan schemed to garner Harley's full attention, and in January 1999, Susan faked an illness to prolong her and Jim's stay in Springfield. Susan sought to unite Jim and Harley, but her matchmaking endeavors failed. Phillip and Susan didn't get along, and he urged Harley to let Jim and Susan lead their own lives. When Harley became pregnant with Phillip's child, a hurt Susan left town with Jim. Susan later reached out to Harley, and the mother and daughter kept in contact without Jim and Phillip's knowledge.

In February 1999, a fleeing Susan called Harley from the bus station after being accused of shoplifting. When Harley went to get her, a mugger attacked the two. Harley overpowered him, and Jim arrived to help them. Phillip arrived, too, and he and Jim argued about Harley's intervention in Susan's life. Because mother and daughter refused to part from each other, Phillip convinced Jim to move to Springfield by offering him a position at Spaulding.

Not long after, the Nursery Rhyme Stalker, Holly Reade, kidnapped Susan, along with other Springfield children, and took them to an abandoned summer camp. Susan tried to escape with the other children, but Holly caught them. Susan and the kids were eventually rescued with the help of Susan's grandmother, Reva Lewis.

Susan tried to play on Harley's jealousy by getting close to Phillip's ex-wife, Beth Raines. One day, Phillip overheard Susan asking questions about miscarriages, and he warned a pregnant Harley that Susan could be dangerous. Jim threatened to leave town over Phillip's accusations, but Harley and Beth persuaded Phillip to convince Jim to stay in Springfield.

In the spring of 1999, Susan caught an orphan named Max Nickerson stealing money from a pinball machine. The two became friends after Susan kept quiet about the theft. Susan and Max sneaked into Buzz's new restaurant to make a dinner. Max dropped a cigarette on the floor, setting the diner ablaze. Cassie Layne rescued Susan and Max, but the fire destroyed the restaurant. Authorities took Max to a foster home. While Harley contemplated pressing charges against Max, Susan helped him escape the foster home. Susan resented Beth's tricks to spend time with Jim. When Susan learned that Jim and Beth were going on a business trip to the Bahamas, Susan hoped that lacing Beth's drink would cause Beth to miss her flight. Susan accidentally drank the concoction herself. Afterward, a dazed Susan took Max to "Make-out Point," and jumped into the lake when Max rebuffed her advances. Even though Max saved Susan from drowning, Jim called social services on him.

As Jim and Harley planned to send Susan to a camp for trouble teens, Susan and Max attempted to run away together. Jim overheard the teens on the phone, and barred Susan from leaving the house. Drew and Jesse arrived, expressing their desire to adopt Max. When they searched for Max at the teens' meeting spot by his mother's grave, they discovered a note from Max, in which he called Susan a traitor for revealing his whereabouts. Susan and Max reconciled their friendship when they both wound up in the camp for troubled teens. Later, Jim and Susan talked their problems through, and Jim took her home.

Susan apologized to Beth, but continued to disapprove of Beth's relationship with Jim. Susan traveled to San Cristobel with Beth, Jim, Phillip, and Harley for Thanksgiving with Cassie and Prince Richard Winslow. Phillip and Beth needed to return home for business, and Jim agreed to fly them in a private jet. The jet crashed, but the three were eventually rescued. Susan realized that she was wasting precious time by remaining angry with Beth, who did really love Jim. Soon after, Jim asked Beth to marry him.

In January 2000, Susan and Max found Beth's prenatal vitamins, and realized that Beth was pregnant. When Jim and Beth arrived, Jim mistakenly accused the teens of making love, and he threw Max out of the house. An angry Susan revealed Beth's pregnancy, and asserted that the baby wasn't Jim's. Jim and Beth married despite Susan's suspicions. Susan tried to mend things with Beth after hearing about Lizzie's leukemia diagnosis; however, she hated Beth all over again upon learning that Lizzie's bone marrow transplant from Beth's newborn son, James, had only been possible because James was Phillip's son, not Jim's.

When Drew and Jesse announced that they and Max would move to New York, Susan tried to seduce Max into staying in Springfield. Harley caught Susan undressing, and put a halt to the seduction. Susan attempted to persuade Jim to leave Beth, and move to New York; however, Jim announced that he'd forgiven Beth, and they would move to Chicago. Selena Davis accompanied Max and Drew to New York, and Max found Susan hiding in the van. During an overnight rest stop at a hotel, he sneaked out to the van to be intimate with Susan. Though she refused, Max finally confessed his love for her. Selena helped Jim locate Susan, but when Susan threatened to run away again, Harley convinced Jim to let their daughter stay with her.

Max returned to Springfield to spend the summer at Buzz and Selena's. He rescued Susan and Marah Lewis when a drunken boy attacked them at their own party. Harley and the cops busted up the party, and Harley threatened to inform Jim about it. Susan ran away, and when investigators found one of her shoes, they presumed foul play. Newcomer Sam Spencer found Susan hiding at the lighthouse, and helped her decide to return home. Harley explained to Susan the circumstances of her adoption, and mother and daughter reunited.

Sam and Susan concocted a scheme to sell pirated CD's to pay their way to see the Nu Ground band perform in Chicago, a trip they'd planned with Marah and Shayne. Tony Santos sold the CD's, enabling the teens to go. When they returned home, they were shocked to learn that the FBI had visited their families, and confiscated the Spaulding computers. Susan begged Nu Ground to drop the matter. To her delight, Nu Ground not only dropped the charges, but they visited Springfield, too. Later, Susan worried that her dreams about Jim being in danger would come true. Shortly before Christmas, a fire broke out at the Lemay home. Jim perished in the fire after rescuing James and Lizzie from the blaze. Susan and Beth witnessed the tragedy, and when Harley tried to comfort Susan, Susan shunned Harley, preferring the comfort of Beth and Edmund.

In 2001, Beth moved with Edmund to San Cristobel , and Harley reluctantly allowed Susan to visit them. During the visit, Susan approved of Edmund wooing Beth, and defended him to everyone who disapproved of him, including Harley. In February, Susan and Harley made headway in their relationship, but Susan felt out of place. With Harley's permission, she enrolled in an out of town boarding school for the performing arts. She managed to mend fences with Phillip before she left. In May, Susan attended Edmund's coronation in San Cristobel. After spending summer break with Harley in Florida, Susan returned to boarding school.

In 2007, Harley and her new husband, Gus Aitoro sought to adopt Sydney, an abandoned baby that they'd found during a police bust. Needing a statement from Harley's firstborn, Harley and Gus visited Susan's school, and learned that Susan, who went by Daisy, was not the sweet, innocent girl that Harley thought. Though Daisy wasn't there at the time, she called Harley, and quelled her concerns with lies.

After burglarizing Harley and Gus's house with her boyfriend, Mark Gillespie, A.K.A. "G," a strung-out Daisy lay in the back seat of G's car. G suddenly struck Tammy Winslow, and fled the crash scene. Gus discovered Daisy passed out in the back of the car. He tried to convince her that G was a criminal, but she insisted that G had hit Tammy by accident. Gus covered the fact that Daisy had been in G's car, hoping to prove that she was just as much G's victim as Tammy had been. When Tammy died, G tried to convince Daisy to leave town with him. Gus urged her to quit the drugs and G, and rejoin her family. Gus set a drug counseling appointment for Daisy, but she skipped it to search for G. Police soon apprehended G, and extradited him to Australia.

Gus thought he'd buried Daisy's link to Tammy's death; however, when Daisy testified at Sydney's custody hearing, opposing counsel forced her to reveal on the stand that she'd been in the car when G had struck Tammy. Defense attorney Donovan painted Daisy as a junkie, and suggested that she may have been driving the car instead of G. Hoping to protect Daisy from becoming G's accessory to murder, Gus revealed that he'd found her in the backseat of the car. The judge denied Harley and Gus custody of Sydney, and expressed concerns that Harley's absentee parenting had adversely affected Daisy. Daisy felt that Harley blamed her for losing Sydney. Instead of returning to boarding school as Harley had instructed, Daisy secured a fake ID to get into Outskirts. There, she attempted to seduce Donovan into persuading his clients to give the baby to the Aitoros. Harley found them, and foiled Donovan's plans to take Daisy to his room.

Harley realized that her troubled daughter needed structure. She enrolled Daisy in public school, and set her up as a candy striper at Cedars. Daisy and her mother immediately clashed, and Reva intervened to Harley's dismay. Gus lent his support to the teen, hoping that he could help her understand her mother. Daisy developed a crush on Gus, and gifted him a stolen watch, and he promptly ordered her to return to the store. Daisy didn't fit in at school, and Harley encouraged her to befriend Leah Bauer. Though Daisy didn't want to attend the school prom, Harley found her a date named Bobby, and insisted that he was a good kid. Bobby canceled on Daisy, and Gus offered to walk her to the dance. Once Bobby heard rumors of Daisy's alleged promiscuity, he lured her to a Beacon hotel room to have his way with her. Hoping to escape the locked room, she pretended to go along with him, but secretly drugged his vodka with pills she'd stolen from a backpack at school. In an attack of conscience, Daisy tried, but failed, to revive Bobby. She called Gus and Harley, but by the time they arrived, Bobby was conscious and lying about what had just happened. Harley believed Bobby over Daisy, and put Daisy in jail overnight to teach her a lesson. A rift grew between Daisy and Harley. While consoling Daisy, Gus leaned in to give her a kiss on the cheek. She moved her head, causing him to kiss her lips. Gus was deeply apologetic, but Daisy was starry-eyed.

Later, Daisy and Harley got into a vicious argument, and Harley slapped Daisy. Daisy responded by pushing her mother. Harley threw Daisy on the couch, and demanded some respect. Daisy appealed to Billy, pleading the case for Dylan to return to town, and Billy offered Dylan a job at Lewis. After Daisy got into a minor traffic accident while taking Zach for a treat, Harley accused Daisy of endangering her little brother's life, and announced that she was sending Daisy to a boot camp. Daisy looked for Gus to help her, but when he kept silent, Daisy hid at Reva's house to evade the boot camp supervisor. Reva stood up for Daisy, but Harley was adamant about sending Daisy away. Gus volunteered to drive Daisy to the camp. During an overnight rest stop at a hotel, Daisy professed her love for Gus. When he responded that he only loved her as a daughter, Daisy sneaked pills into his drink. After he passed out, she lit some candles, and crawled into bed with him. The candles caught fire, and a panicked Daisy called the paramedics when she couldn't revive Gus to make an escape. At the hospital, Daisy pretended to be his girlfriend. While Gus lay in a hospital bed, she heard him mumble, "Natalia."

Daisy lied to Dylan and Harley that Gus had taken pills, and Dylan blamed a pill popping Gus for the fire. Gus attempted to talk to Daisy about her feelings for him, but she recanted her profession of love. Dylan found Daisy's video blog, in which she discussed her love for Gus, and Dylan became convinced that Gus was a drug addicted sexual predator. After Harley broached Gus with Dylan's concerns, Gus revealed Daisy's crush on him. They realized that Daisy had drugged Gus. The pair confronted Daisy, and she grew upset that Gus took Harley's side over hers.

Later, a bitter Daisy found the mysterious Natalia in Chicago, and upon learning that Natalia still had feelings for Gus, Daisy hinted to Natalia that Harley and Gus were having marital problems. Daisy lied that she was throwing a party to cheer her stepfather up, and invited Natalia to attend. A traffic ticket from Chicago proved that Daisy had violated her parole by leaving Springfield. In court, Harley confessed to the judge that she could no longer handle her daughter, and the judge sentenced Daisy to three months in juvenile detention.

While serving her sentence, Daisy befriended inmate, Ashlee Wolfe, and became enamored by a Latin American teen, whom she referred to as "vent boy" because they talked to each other through the vents in their rooms. Daisy refused to see or speak to Harley, but she allowed Gus to visit. He expressed his anger that Daisy had lured Natalia to Springfield. Dylan took Harley to see Daisy, and he confessed that boot camp had been his idea. Daisy softened toward Harley, even hugging her. Dylan used some of his connections to get Daisy out of juvie. Before Daisy went home, Harley informed her that Gus had just learned that he'd fathered a son named Rafe with Natalia. Rafe, who was Daisy's age, was staying with them. When Daisy arrived home from detention, she was shocked to see that Rafe was "vent boy."

Rafe and Daisy pretended that they'd never met, so that they could carry on their relationship under the same roof. Their secret caused Rafe and Harley to butt heads until Daisy finally revealed the truth about her relationship with Rafe. Harley and Natalia agreed that it was wrong for the teens to live under the same roof, and even though Daisy moved in with Dylan, their parents still forbade them from seeing each other. The teens resumed sneaking around. They were found out when Rafe went into insulin shock during their secret date at the Spaulding lake house. Harley insisted that Daisy move back home, but Gus refused to kick Rafe out. Rafe and Natalia moved into the Spaulding mansion. Daisy tried to strike an allegiance with Natalia, in which Daisy would help Natalia win Gus in exchange for time with Rafe. Natalia accused Daisy of sacrificing her mother's marriage for her own interests. Daisy struck back by telling Buzz that Natalia was after Gus. Buzz fired Natalia from Company, and Rafe admonished Daisy for hurting his mother. While at Cedars visiting Dylan, who'd been in a car accident, Daisy shoplifted a watch from the gift shop. The clerk caught Daisy and Rafe attempting to leave the store with the merchandise. Rafe called Alan, who paid for the watch, and even bought two more. Weeks later, Daisy and Rafe declared their love for each other, and made love at the Spaulding lake house. More time passed, and Daisy seemingly pulled herself together. However, around the time she won vice president of the student council, she also discovered that she was pregnant.

Daisy confided in Reva about the pregnancy, and Reva advised Daisy to consult her mother. Daisy agonized over how to handle it, and eventually took herself for an abortion. When she finally revealed her choices to Rafe, he turned from her, unable to reconcile that she'd done something against his Catholic religion. Daisy felt the heat of Natalia's wrath, as well. Harley and Dylan comforted their daughter, and as Daisy slowly regained her life, it appeared that Rafe's life was falling apart. Things drew to a head when an angry-at-the-world Rafe got drunk, and disrupted Thanksgiving at Harley's house. Daisy went to Rafe, and confided in him that she'd felt empty inside ever since the abortion. Rafe finally started softening as he held her.

In 2008, Daisy and Rafe's relationship continued to mend, and she looked forward to college. Daisy turned on divorcee Harley after catching her kissing Marina's fiancé, Cyrus Foley. Disgusted by her mother's actions, Daisy moved out of the house, and suggested to Rafe that they find a place of their own. Daisy tried to scam money off Harley for a deposit on an apartment by lying that she needed money for a school trip. She lashed out at Harley when Harley had no money to spare. Daisy started a business with Rafe selling fake ID's to raise the money for their apartment; however, Cyrus quietly shut their operation down without involving Harley. After Gus's sudden death in a motorcycle crash, Rafe nixed plans to move in with Daisy to be there for Natalia. In his grief, Rafe turned cold to Daisy.

Desperate for money, Cyrus wanted to revisit Daisy's fake ID business. Though Daisy despised Cyrus, she agreed. They were quickly caught when a teen carrying one of their ID's ratted them out to Harley. Matters worsened when, on the eve of high school graduation, Daisy revealed to Harley that she'd been suspended, and might not graduate. Cyrus solved the problem by telling police that he'd forced Daisy into the fake ID business. On graduation day, Rafe shot Jeffrey, and went on the run. Daisy found him hiding in the house that Gus had bought before his death, and she convinced Rafe to call her mother. That same day, Rafe disappeared, and Harley left town without saying goodbye. Daisy eventually learned from Cyrus that Harley had taken Rafe on the run to avoid prosecution.

Not long after, G returned to town, despite still being wanted in connection with Tammy's murder. Daisy hid G from the police, and when Cyrus discovered them, he shockingly revealed that G was his younger brother, Grady Foley. Cyrus warned her that Grady was bad news, but she continued to hide him in Reva's storage shed, giving him money that she'd stolen from Company. When Daisy learned that Grady was the mysterious man who'd been flirting with Ashlee, Daisy spitefully called the police on him. She was confused about her feelings for Grady, and her family insisted that he was bad for her. When Grady made bail, she defied her family by constantly sneaking out to see him. Daisy refused to listen to reason when it came to Grady, and Frank attempted to ship her off to Greece to live with Harley, but Harley had already fled from that country to parts unknown, presumably with fugitive Rafe. Ultimately, Daisy convinced Grady to make a statement to the police regarding Tammy's death.

Before Grady's trial, Daisy received heavy pressure from her family to testify that Grady, Alan's hired hit man, had subsequently run over Tammy after intentionally aiming for Jonathan. Unable to send Grady to prison, Daisy lied on the stand, testifying that Tammy's death had been an accident. She said that Grady had been distracted from driving after she'd become ill in the car. Daisy's testimony set Grady free, and earned Daisy the disappointment of her family, Jeffrey, and Cassie.

Weeks later, fugitive Rafe stealthily arrived in town. Daisy assured a jealous Grady that Rafe was a part of her past. Rafe met her at the Cooper house, and asked her to run off with him; however, she declined because her feelings toward him had changed. During their discussion, the police surrounded the place. An anonymous call had tipped authorities off that Rafe was armed with a hostage. Rafe surrendered, and went to jail to await his trial for shooting Jeffrey. Daisy attempted to rehabilitate Grady in the community by getting him a job with Dinah Marler. When Daisy learned from Cassie that Grady had made the anonymous call, Daisy reluctantly dumped him.

Daisy found a new career for herself when she one day realized that a kid had a fake ID. Suspecting that he had drugs, too, she notified the police. Daisy pitched the idea of forming a youth task force comprised of undercover agents like herself, who would be devoted to catching youthful offenders. Doris implemented the task force with Daisy as the first agent, and agreed to move up Rafe's trial based upon Daisy's effectiveness. Later, a renegade Daisy conducted a sting alone, and her suspect took her hostage. Mallet and Marina arrived on the scene, and Daisy stabbed her captor with the key that Grady had given her.

Mallet and Marina bought Harley's house, and asked Daisy to move in with them. They tried to keep Daisy away from Grady, but she was still vulnerable to him. Daisy and Ashlee were also suspicious of Grady and Dinah's relationship. Daisy spotted a crashed van with Bill and Lizzie inside. Inspired by Lizzie and Bill's devotion to each other, Daisy reconciled with Grady, but never learned that Dinah and he had kidnapped Lizzie. The Coopers and Lewises were bitter about the reconciliation. Insistent upon proving that Grady was still a bad guy, Ashlee tried to set Grady up as her attacker; however, when Grady saved her from a real attacker, he earned Buzz's respect. Daisy moved in with Grady, and Frank implored her not to let Grady take her from their family.

In 2009, Daisy encouraged Bill not to give up when Lizzie suspected that he was her kidnapper. Though Bill had no memory of the kidnapping, Daisy was certain that he was innocent. Daisy encouraged Bill to go to a hypnotherapist to retrieve his memories.

When Coop died in a terrible car accident, a distraught Buzz sought revenge on Alan. Buzz urged Grady to testify that Alan had hired Grady to kill Jonathan. Grady reluctantly agreed to do it when he saw how important it was to Daisy, but he never showed up at the hearing. Daisy and Buzz searched for Grady, but he'd completely disappeared. Ashlee told Daisy about Grady's part in Lizzie's kidnapping, and Daisy refused to believe it at first. Convinced that Alan had something to do with Grady's disappearance, Daisy took Marina's gun to the Spaulding mansion, and demanded answers from Alan. Daisy fired at Alan, but missed. Buzz arrived, and convinced her to let it go. Daisy's hatred for the Spauldings consumed her for a long time. When Marina and Mallet asked her to be Henry's godmother, Daisy refused to be the "cute little Daisy" they wanted her to be. The couple's second choice, Dinah Marler, stepped down after admitting her part in Lizzie's kidnapping, and Natalia convinced Daisy to be the godmother after all.

Later, Daisy visited her old dorm room in which she'd met Grady years earlier. It had been converted to a men's dormitory, and the new occupant flirted with her. He asked her to Towers for dinner with his family. Once there, Daisy realized that her new friend was James Spaulding. Though Daisy claimed to be disinterested in James, she seemed affected by his charm. When James invited Daisy on a family trip to Universal Studios, she declined. Ashlee and Christina talked her into going, and finagled themselves a trip there, as well. Despite her reluctance, Daisy had a good time in Florida, and continued to bond with James.

At one point, James admitted to Daisy that he'd initiated a Ponzi scheme in an attempt financially free himself from the Spauldings. The market crashed, and James had no money to pay his investors. Daisy offered to help James with a new investment scam. During their meeting with James's client, Daisy realized that James was using Bill Lewis' name to trick investors into trusting him. She kept James's secret, but divested herself of the business. While Phillip prepared to take the fall for James's Ponzi scheme, James invited Daisy to partner with him in another fraud that didn't involve Bill. Phillip caught Daisy and James meeting with an investor, and put an end to their partnership. James refused to quell his ambitions, and when Phillip again caught James soliciting investors, he turned James into the authorities. Phillip bribed the judge into giving James community service, and Alan Spaulding bought James's way out of it. Daisy worried that Alan was a bad influence on James. Alan worried the same thing about Daisy, expressing that Coopers and Spauldings shouldn't mingle. James agreed to be Alan's protégé, but was adamant that Alan not interfere in his relationship with Daisy.

Daisy showed her maturity by pitching in to help her family through tough times during the summer of 2009. She constantly babysat for Marina and Reva, and she flew Colin to be with Reva as she searched for her missing husband, Jeffrey O'Neill. Daisy worried about Reva when she saw that Reva had plastered pictures of Jeffrey all over Cross Creek. After Reva assured Daisy that she'd be okay, Daisy kept her secret. Daisy wanted to go to college, and received a tuition check from an anonymous benefactor. She applied to Berkeley, and pretended not to be crushed when she wasn't accepted. The Coopers received more anonymous gifts, and eventually learned that Cyrus Foley had been using money he'd gotten from fencing stolen diamonds to help them.

Daisy and Rafe continued their friendship, and he gave his blessing for James to pursue her. Though she still refused to admit that she was falling for James, they spent a lot of time together, eventually making love while on a camping trip. Daisy was there for James as he struggled with his conflicting feelings for Phillip. At first, Phillip tried to separate Daisy and James, but he grew to appreciate Daisy's influence on his son. When James discovered that Phillip was dying, he grew angry that Phillip wouldn't let him undergo a dangerous procedure to save Phillip's life. Daisy was glad because she didn't want James to die. Alan submitted to the procedure instead, and died shortly after. Daisy consoled a grieving James.

A representative from Berkeley called Daisy to say that a spot had opened up for her in their freshman class, but she had to leave home immediately to take it. Buzz urged her to go, saying that the proceeds from Coop's book would pay for it. James encouraged her to go as well, and promised to visit her. Doris Wolfe finagled a spot for Ashlee at Berkeley, and Daisy and Ashlee decided to share a house in California. Before Daisy left, she and James said that they loved each other. They continued to date while she was in school.