Cait was born in 2261 to a distant and abusive family of Irish1 descent. She had tried to run away from her parents twice; the first time, she was locked outside in a shed, the second time, they broke one of her legs. On her eighteenth birthday, Cait's parents sold her into slavery. For five years, she stole small sums of bottlecaps from her owners, until she had enough to buy her own freedom. In a pique of rage, she returned home to seek vengeance on her mother and father and shot them both dead.

At some point after she left home, she began using psycho, developing an incurable addiction. Sometime later, she arrived at the Combat Zone in Boston, and was hired by owner Tommy Lonegan as a cage fighter, soon becoming a strong and ruthless fighter. In 2287, a raider gang moved into the area, which then required Cait to buy friends to make life easier, making the cage fighter mistrustful of selfless offers of kindness.