Gabrielle first appears when former boyfriend Max Holden (James DePaiva) visits her native Argentina with his new girlfriend, Tina Lord (Andrea Evans), in 1987. Gabrielle's drug lord father, Dante Medina (Henry Darrow), is killed and Tina is presumed dead after plummeting over the Iguazu Falls. She turns up alive as Gabrielle secretly gives birth to Max's son; Gabrielle is soon duped by Tina into letting Tina pass the child off as her own. Gabrielle believes that Tina is raising the child with Max, but Tina actually pretends the child is hers with estranged husband Cord Roberts (John Loprieno), hoping to reconcile with him. Gabrielle moves to Llanview in July 1987, and the truth is eventually revealed, leading her to reunite with her son, Al. Max and Gabrielle fight their passionate attraction to one another after she marries his brother, Steve Holden, in 1988. After Gabrielle and Steve divorce, she orchestrates a baby switch to prevent her friend Michael Grande (Dennis Parlato) from learning that his newborn son actually died; Gabrielle and Michael get engaged, but once the switch is exposed, the relationship ends. Gabrielle goes on trial but is given a slap on the wrist; she and Max reunite and marry in 1990. In 1991, mob boss Carlo Hesser (Thom Christopher) blackmails Gabrielle to aid him in his plot to poison newspaper publisher Viki Lord Buchanan (Erika Slezak). Gabrielle eventually backs out and testifies against Carlo in trial for Viki's attempted murder. She ends up accepting the blame and goes to jail for seven years to protect her young son Al from Carlo's wrath in 1991.
After her stint in Statesville Prison, Gabrielle returns to Llanview in 2001 and marries billionaire Asa Buchanan (Philip Carey) as part of her scheme to destroy Max, with whom she is angry for being a dead-beat father to Al. Gabrielle and Asa's plot to fake Asa's death and frame Max for his murder fails, and after their divorce, she attempts to change her scheming ways by dating Police Commissioner Bo Buchanan (Robert S. Woods). Her insecurities over Bo's friendship with his ex-wife, Nora Hanen (Hillary B. Smith), nearly ruin their relationship, but Gabrielle and Bo become engaged shortly after Al's tragic death in 2003. Just as she has found happiness again, Gabrielle is murdered in January 2004 by Dr. Stephen Haver (Matthew Ashford).
When Bo are shot by deranged escaped convict Troy MacIver (Ty Treadway) at the series finale in 2012, Gabrielle reappears in Heaven, encouraging an unconscious Bo that he had more "life to live."