Isabelle is introduced shortly after Royce a mercenary, Chuchillo a cartel enforcer, and Nikolai a Spetsnaz. She joins them out of survival. Her more moralistic personality clashes with Royce's self serving mentality. After their first encounter with the Predators Isabelle punches Royce in the face for using them as bait. Royce then reveals that Isabelle knows what they are from the way she looked at a captured Predator at the camp. Isabelle then gives an abridged version of the events of the first Predator encounter from the first film.After encountering Noland, a survivor on the preserve, Isabelle reveals that while she was back on Earth her spotter was captured by enemy forces. She could have saved him but that would given away her position and probably have gotten them both killed. While she feels survivor's guilt Royce tells her she did what she had to survive. Isabelle then realizes that the Predators took them because they are killers just like them and that it's better that they're never going back home though Royce remians adamant in commandeering the Predators ship and going home. After Noland attempts to kill them, the group makes a break for it outrunning the Predators, but lose members one by one till only Royce, Isabelle, and Edwin remain. After Edwin trips a bear trap and critically injures himself, Royce opts to leave him behind. Isabelle won't saying that he's part of the group, and Royce says that's exactly what the Predators are counting on. Isabelle refuses to abandon Edwin and Royce takes off. Edwin and Isabelle are later captured by the Berserker Predator and tossed into a hole, while there Edwin cuts her with a scalpel laced with a neuro-toxin he found in the jungle and paralyzes her. It's there that Edwin reveals his true murderous nature to Isabelle and that he wants to stay on the preserve, but first he's going to kill Isabelle and it will be painfully. Royce however comes back from them, having had a change of heart. Edwin attempts to kill Royce but Royce pulls a fast one on him and uses him for bait. When the Berserker Predator turns the tables on Royce Isabelle, still somewhat paralyzed takes a shot at the Berserker Predator and manages to hit it and gives Royce the chance he needs to kill it. After Royce kills the Predator he and Isabelle introduce themselves to each other and they take off into the jungle still stranded on the preserve.
Predators: Preserve the Game
Set several months after the events of Predators, Royce and Isabelle have separated. Royce however comes back after getting sick of being alone and he and Isabelle begin a more intimate relationship. Shortly after the Predators drop a package full of armor tailored specifically for Royce and a four armed Predator shortly after. Royce and Isabelle attempt to repeat their feat with the Berserker Predator, but Isabelle misses the shot. Royce still manages to kill the Predator though he and Isabelle still remain stranded on the preserve
Clashing with Royce's more self-serving personality, Isabelle is more moralistic. Where Royce is only in it for the money and doesn't care about any life but his own, Isabelle justifies her killing because she's in the army and never has to admit she likes it according to Royce, though she denies it. Isabelle does value human life, such as her reaction to mercy killing Chuchillo and refusing to abandon Edwin, though Isabelle does not value her own. When Isabelle realizes the Predators took her because she's a killer like them, she decides that it's better that she's never going back to Earth. However after Royce saves her from Edwin, Isabelle begins to value her life again and continues on surviving with Royce.
While the character is Israeli, the actress playing Isabelle, Alice Braga, herself is Brazilian. As the only female character, Isabelle plays the role of peacemaker: "My character, funny enough," said Braga, "is the one that is always trying to grab everyone together and like reuniting everyone and stop[ping] the fights and saying that we have strength in numbers." Braga described the character as "a tough cookie ... sweet inside but tough outside". She read a sniper manual to prepare for the role, and carried a fourteen-pound sniper rifle during shooting.