Brother and 2 sisters father is getting out of prison drama

Help me find this movie. British (English) movie teenage girl (wears her hair in a bun) poor. Lives with her brother and younger sister, father abused them and is in prison but getting out soon: they have a social worker. The teenage girl gets involved in a jeweller pawn shop and becomes friendly with the man who works there? He drives a Land Rover. She becomes close with a blonde hair girl who lives in a big house and she turns out to be the man’s daughter and she kills him?