This was a hard book to read, for many reasons. The trigger warnings at the start of the book are very important: particularly the fact that there is sexual abuse of a child. 
This book read far more as a psychological thriller than horror to me. The supernatural elements felt forced and incidental to the main story, and I never really understood how they fitted in.
The ending was clever, and - to me at least - unexpected. I felt that I needed to go back and re-read to see what I'd missed, but I didn't enjoy it enough to want to do that. While I felt very sorry for the main character, Bethany, she was never particularly likable or even very well fleshed out. The whole novel is full of unlikeable characters, and that always makes me struggle with a book.
It was an interesting read, but unfortunately, clarified to me why horror and psychological thrillers really aren't my thing at all.