Another fourtris tale

Tris is an 18 year old trapped in her father's care and she cannot escape. After her mother died when she was 10, he's blamed Tris for her death and abuses her verbally but also physically. Why doesn't she call the police?? Her father is the chief police officer which prevents her from contacting the police of any sort. She has never told anyone about this since she has no friends due to bullying. Her first day of a new school is close. What happens when she starts making friends, will it be harder to hide??