Gina was a bitter, troubled sex addict with a history of self-destructive behavior. She was later revealed to suffer from Borderline Personality Disorder. Along with other conditions, she would have sex with different partners and forget their identities. Her Sexaholics Anonymous group calls this "Blackout Sex".
Her favorite type of sex was anal, though she was also a huge fan of vaginal penetration. At her funeral, she was praised as giving the best blow jobs and hand jobs around. She was also credited as being extremely well-adept at cunnilingus.
Months later Gina revealed to Christian she was HIV-positive, which forced Christian to rethink his life as he called up every girl he had sex with since his relationship with Gina to warn them, and then tracked down James and Wilber (who had since been renamed Gabriel) so they could be tested - all three were HIV-negative. James convinced Christian to see the good in Gina, and he eventually forgave her. Christian ended up paying for Gina's HIV medication (upon finding out that she was without any health care insurance and was not on any HIV medication), and the rent for her apartment.
The two had since developed a friendship, though that quickly changed when Christian's money troubles forced him to stop supporting her.
In the Season 3 Finale, Gina was attacked at Troy/McNamara surgery by the Carver, a masked serial killer who had taken a special interest in the partnership's clients. Later when asked by Sean and Christian, she explained that she was there to ask Christian to be her date. Christian refused, saying that he did not want to ruin their friendship.
Unable to support her medications for HIV treatment, Gina soon found a way to support herself by embarking on an ambitious business venture with Julia McNamara, a surgical recovery spa called "De La Mer".
Gina found a creative way to keep down costs on "De La Mer". Gina's self-destructiveness continued when she began to offer oral sex to contractors and construction workers (male and female) in exchange for reduced fees. Julia was horrified and, for perhaps the first time, offered her validation and told her she is too good to be doing such things to herself.
At the beginning of Season 4, Julia explained that she sold out her share to Gina, leaving Gina as the sole owner of the spa. At the end of the season, it was revealed that Gina sold the spa for a large profit.
Gina returns in season 5 at the request of Dr. Sean McNamara to be the office's new receptionist. At first, it appears that Gina has turned over a new leaf, by acting friendly towards Christian. Her attraction to him was still evident, and they engaged in what she called "post-modern sex"--Gina watching as Christian had sex with a prostitute who resembled her, so that Gina could experience intimacy with Christian without risking the chance of passing HIV to him. Gina later tells an extremely ill Julia that Christian has cheated on her. In their final encounter, Christian and Gina begin to have sex on the roof of a building. However, while engaging in intercourse on a rooftop, Christian accidentally pushes Gina off the rooftop, killing her. Her funeral takes place in the following episodes, with many of Gina's sexual partners paying tribute to their experiences with her.