The stakes are so high with our children, adults or not, that often posts like this get few responses. Just know that it isn't because there's a lack of caring about this, it's more likely that there's too much caring and too much at stake if somebody gives advice that does not pan out in a good way.
I can't imagine what I'd do in your shoes. My daughter will be 20 in five years, and the way she's going right now I could easily end up in your shoes. Whatever you do, if you do what you believe is right and best then there you go. Just be prepared for any outcome, good or bad (and I think you already are).
Good luck,
Cyranoak