Rebecca was an edgerunner of Night City, who was always fighting with her brother Pilar. The two siblings often teamed up with Maine and his crew to conduct mercenary jobs, although their daily life outside of work was tense, since they would always fight with each other, because of Pilar's provocative behavior, this caused her to decide that she would be the person to kill her brother someday.

Some time prior to the day Sasha Yakovleva died, their crew was hired to infiltrate the Biotechnica's Night City HQ to extract secret financial records and information. They got drinks in the Afterlife before sending Sasha, the crew's netrunner, to infiltrate the building.

Rebecca first meets and works with David Martinez during a limo heist, distracting Maxim by spilling booze on him and sensually cleaning it. The distraction fails once Maxim notices his keys have been snatched, calling her a ♥♥♥♥♥, to which she replies that he's weird. She is immediately attracted to David and attempts to flirt with him at the mission after party. When David is working his way up in Maine's crew, he is sent to deliver a pair of cyberarms to the apartment that Rebecca and Pilar share. She is also seen helping David practice with firearms, impressing him greatly by hitting every target in exact spots while dual wielding. Rebecca seems to be a fan of cyberpunk culture in general, as she is seen excitedly pointing at Rogue Amendiares when seeing her at the Afterlife.

One night while the crew is out walking, Pilar is killed by a cyberpsycho, sending Rebecca into a rage. She instantly rushes the cyberpsycho and is almost killed herself, before being tackled behind cover by Maine. After the cyberpsycho is killed by David, she continues to shoot the corpse out of rage for killing her brother.

After reforming a new crew with David following Maine and Dorio's deaths, she is seen with large cyberhands, mimicking the behaviors of her late brother, likely out of love and respect for him. She has also become the secondary muscle of the crew, behind David, who is now the leader. Rebecca is extremely skilled and reliable in combat, even saving David's life on an occasion where he freezes up due to oncoming cyberpsychosis. She attempts to confront him about it, telling David she watches him closely and notices something is wrong.

Rebecca is next seen just before she, David and Falco embark to intercept an Arasaka convoy under Faraday's orders. By now, David has already begun his steep descent into psychosis and Rebecca catches him, nearly collapsed, in the lounge of their hideout. He implores her to help him stay sane by injecting him with the 9x dosage suppressants he got from Doc. She begrudgingly accepts, on the terms that he doesn't use his Sandevistan, which he violates. She is seen throughout the mission manually injecting him with meds, as she promised, despite becoming increasingly worried for his safety. After Faraday and Kiwi's treachery is uncovered, she and Falco agree to help David rescue Lucy by assaulting Arasaka Tower, though they eventually end up landing the Chevillon Emperor in Corpo Plaza instead and being surrounded by Arasaka troops and NCPD.

When David manages to rescue Lucy, Rebecca tells her she's glad that she's safe for David's sake. Moments later, she notices Adam Smasher falling toward them and shoots up at him, only to be crushed under his weight, her last words being "We are having a moment here! ♥♥♥♥ you!"

Lucy wrote "I regret not finishing our conversation" on Rebecca's niche in Night City's Columbarium.