Although I enjoyed reading another book by Robbie Branscum, I quit reading this one after the first few pages. Though the story and language probably does reflect the situation and circumstances, I found it crude and not suitable for most children. What other cruelties might be described, I don't know, but it does cover sexual abuse. Since I didn't read much of the book, I can't say in what detail it might be described throughout the book. I recommend that you read this book before giving it to a child, so you will be able to discuss and address the story with him/her.
In all fairness, I will add that "The Girl" was an ALA 1986 Best Book for Young Adults.
From School Library Journal--Although this is the story of physical and sexual abuse, neglect, and emotional isolation, it is ultimately the poignant story of human endurance, love, and hope in a seemingly hopeless setting. The vivid picture of rural Arkansas, coupled with characters and relationships developed to their full human complexity, make this a memorable novel.