I'm sorry you're going through this with your daughter. Hugs for the both of you.
I don't know the laws in NC, but we were in Texas when our son was 16. I was floored by the laws there. I think it was at age 17 that I could no longer force him to do anything (it became kidnapping, etc) but I was responsible for his school attendance until he was 18. Go figure. We got through it, you will too.
My advice would be to check on your legal rights and legal obligations.