She is the daughter of Kelly O´Brian, who protected her, when the Xenomorphs came to Gunnison, Colorado. Her father was one of the first to die. She, like Newt, sees the Xenomorphs as monsters.
After the death of her father she and her mother joined others in their quest to survive and, in the end, she also became one of the four survivors of the Gunnison disaster like her mother because of her mother´s realsiation about the military´s intentions to blow up Gunnison to prevent the Xenomorphs from spreading.
After they have survived she asks her mother, if the monsters have gone and she answers yes.