Sally Sarasota was a former female wrestler with twin daughters that wound up being killed by a drunk driver while walking home from school one day. She tracked down the driver, chained him to the rear bumper of her car, and drove around his neighborhood at 20 mph for half an hour until the police cornered her. She was incarcerated at Arkham Asylum until she was released by Knightfall so that she could join her Disgraced.
Every day she still makes breakfast for her daughters and tells them stories at night.
Bonebreaker was created by Gail Simone and Alitha Martinez, and she first appeared in 2012's Batgirl #10. Her character didn't get a full introduction as "Bonebreaker" until the following issue though.