Grace by Morris Glietzman (Children's)

Summary from Puffin In the beginning there was me and Mum and Dad and the twins. And talk about happy families, we were bountiful. But it came to pass that I started doing sins. And lo, that's when all our problems began..

This is a book I've re-read recently. The full and rather long review is here. 10/10 to story of a girl in a cult, who gets in trouble, and starts to try and escape from the cult members, which include her family.