She may not want to talk to you or your husband but may be able to talk to a counsellor knowing thats its in confidence and can't be repeated to anyone including you.
Sorry, but that's not true. You'd be surprised at just how much that's said "in confidence" to teachers, doctors, school guidance counsellors etc is reported up the chain, whether or not that action is actually likely to help the person in question.
Alison, I think you're right to be cautious and to try and talk to her yourself without making too big a scene out of it if possible. A lot of girls do this sort of "stupid" thing at that age and thankfully most of them grow out of it, no point in calling in the quacks and making her feel even more set against; every point in speaking to her and keeping a close eye out for it in future...