1996
Bobbie Spencer's biological daughter, Carly Roberts, arrived in Port Charles and plotted to steal her mother's husband, Tony Jones. She also struck up a friendship and brief sexual relationship with Jason Morgan. By the time her identity was discovered by her uncle Luke Spencer, Carly had already seduced Tony and Luke chose to keep her secret.

1997
After a bitter fight with Tony, Carly bedded a drunk A.J. Quartermaine. When Carly went to A.J. to convince him not to reveal their one-night stand, she learned he did not remember it. Carly realized she was pregnant and passed the child off as Tony's. A.J. eventually remembered the night he and Carly had made love and that he might be the father of her baby. When Carly discovered that Tony planned to leave her and get custody of the baby, Carly claimed that the child was her former lover Jason's.

1998
After suffering from post-partum depression, Jason and Bobbie helped Carly reconnect with her son, whom Jason had named Michael. Carly revealed that she was really Caroline, the daughter Bobbie had given up for adoption as a teenager. Tony Jones was prosecuted for running away with Michael, but when a jury handed down a minor sentence, Carly shot her former lover in open court and was sentenced to serve time in Ferncliff, a mental institution. After Jason secured her release, Carly and Michael moved into the cottage with Jason and his girlfriend Robin Scorpio.

1999
Robin told A.J. that he, not Jason was the father of Carly's baby. Bowing to A.J.'s blackmail — he threatened to have her sent back to Ferncliff — Carly moved into the Quartermaine mansion hoping to land a big financial settlement by driving A.J. to drink and then divorcing him. A.J. proposed to Carly and they wed, though she plotted a future with Jason. Carly misread a close moment between Jason and Elizabeth Webber and slept with Sonny causing Jason to inform Carly that they could never be together.

2000
Carly learned she was pregnant with Sonny's baby. Carly planned to make love to A.J. and pass the child off as his, but the plan backfired when A.J. realized she was already pregnant and he couldn't be the father. However, A.J. promised to raise the child as his own and Carly agreed. Sonny learned from Bobbie that he was the true father and blackmailed A.J. into relinquishing his parental rights and divorcing Carly. Carly and Michael moved into Sonny's penthouse. Sonny and Carly made love and she agreed to be his wife. At the Quartermaine mansion, Carly fought with A.J. and fell down the stairs, miscarrying her child. Carly and Sonny bonded over their loss. Carly and Sonny wed so that she wouldn't have to testify against him in court, but after the charges were dropped, Sonny and Carly chose to stay married.