I found this interesting article about the 1993 disappearance of thirteen-year-old Deanna Merryfield. Her twin sister was interviewed. The family had a lot of problems: alcoholic mother, sexual abuse of Deanna by a relative, they were passed back and forth among various members of the family. The twins were separated at the time Deanna went missing; she was with a grandmother, and her sister was with an uncle.
Deanna’s sister believes she ran away and is still alive, and from the sounds of it that’s a very real possibility. I hope she calls home. She may not want to be in touch with some of her relatives, but it would be nice if her sister could hear she was safe.