Mary Warwick was conceived through a drunken one-night stand between a married James Warwick and Sheila Carter. After discovering that she was pregnant, Sheila agreed to have the baby and give it to James and his wife Maggie to raise. She went along with her part of the deal and had the baby, which James and Maggie named Margaret despite the fact that Sheila wanted to name the baby Mary after James's mother. Sheila moved to Death Valley and became a waitress where she met Amber Moore. Amber convinced Sheila to fight for her baby. To prove that Sheila was an unfit mother, James divorced Maggie and seduced Sheila into agreeing to marry him. He believed that he could get her into a situation where she would leave the baby home alone, thereby proving she was unfit. The plan failed, but James went through with marrying Sheila. When Sheila found out about the plan and tried to commit suicide. James later fell in love with Sheila and wanted to remain married. James later developed feelings for Stephanie Forrester. To keep Stephanie away from her husband, Sheila threatened to kill Stephanie's grandson. Stephanie had Sheila put in jail for the threat. Sheila later broke out of jail and left town with her daughter, Mary.

Erica Lovejoy went to Los Angeles to meet the person she has idolized for years, Amber Forrester. After Amber miscarried her baby, Erica ran away from the home she shared with her mother to meet her idol. She went to the hospital where Amber was staying and offered her sympathy. She later used Zende Forrester (who she met when she posed as a teacher at his school) to get her into a Forrester party. At the party she met Rick Forrester and was soon offered the job as Little Eric's nanny. She accepted. Soon after, her mother, Sheila Carter, tracked her down and broke into her apartment. Erica knew nothing about her mother's past or that her real name was not even Erica (her mother had renamed her after the only man she ever truly loved, Eric Forrester) or that she was really Mary Warwick. Sheila moved in with Erica and tried to convince her to make moves on Rick Forrester, her boss.

Erica soon found out that Sheila had paid Lance to drug Amber into bed, killed Lance and set Amber up for breaking a window (which sent her to prison). Sheila convinced her not to tell anyone because if the Forresters knew Sheila and Erica were related they would want nothing to do with Erica. Sheila then convinced Erica that if she wanted to be a part of Rick's life she would have to have his baby. Erica wasn't sure at first, but she set up a romantic dinner for her and Rick and tried to seduce him. Rick was still in love with his wife and refused to sleep with Erica. That same night, Sheila kidnapped Amber at gun point and made it look like she jumped parole and went on a drinking binge. While she was holding Amber and about to kill her, she called her lover, Massimo. Stephanie was with him and she recognized her voice and put it together that she was Erica's mother and rushed to Erica's apartment to find her. On the way to Erica's, Stephanie called Ridge and told him to go to Rick's house and warn him about Erica.

Ridge went to Rick's and told him everything about Erica. Erica then confessed that she was trying to seduce him to become pregnant and she begged for Rick's forgiveness. Rick refused to forgive Erica and told her he never wanted to see her again. When Massimo and Stephanie arrived they rescued Amber, but Sheila got away. Sheila went to Eric's house and begged him, at gun point, to not punish Erica for everything. While they were talking Taylor came in and Sheila held her at gun point too. While trying to convince Sheila to put the gun away, Brooke walked in. A scuffle between all of them happened and Brooke and Taylor were shot. For Taylor it was fatal. Sheila was arrested and sent to jail. Erica confronted her mother in jail and told her she hated her and never wanted to see her again. Erica then left town and has not been seen since. It is unknown if she and James have ever met.