Ruth's mom was a polygamist. She met and married Ruth's father to become the prophet's wife. When he was killed she remarried to become a third wife. The man she married was very poor and was a pedophile. None of this apparently matters in the eyes of the lord. What matters is that you stay with your husband no matter what. Even when her mom found out that Ruth was being molested, she stayed. When he stole all her money and gave it to his other wives, she stayed. When they moved back and forth between the US and Mexico and worked to support the entire family, she stayed. Such a heartbreaking story for a little girl to have to go through. To be told "he said he's sorry and it won't happen again" knowing it will as soon as he gets a chance. Pathetic of the mother to put her own feelings first. 

If you have a particularly fragile emotional state do not read this. This book threw me into a mental health crisis. 
The experiences in it are valuable. Ruth Wariner's childhood is fascinating, but gut-wrenchingly tragic and infuriating. I have nothing bad to say about the writing or the book itself.
But please, read with caution and seek help if you are going through a crisis.