There are a few really good books about cutting both non-fiction and fiction, if you would be interested for you. There is also a movie that you might find insightful, it is Thirteen. I would see it without your daughter so you can evaluate its merits.
Quote:
Apparently, she feels it was an awesome thing to do, as though it empowered her.
Not uncommon. It's something she has control over.
I am so very sorry you and your daughter are having to go through this.