I hope this doesn't sound too harsh, but I feel really strongly about it. You can't trust your daughter to do the right thing at home, but you are considering sending her to the other side of the world with people who don't know her or her problems??
The first time Tim went to Thailand I shat myself most of the time he was there and I trust him implicitly(sp). Yes he was a teen - that was part of it - but I had no idea how he'd react in certain circumstances. The ONLY reason he was able to go was because I knew I could trust Dion and Miriam with his life - and yes, it could have come to that!
To be completely honest - if we'd had ANY doubts about his behaviour, he would have stayed home (even though he fundraised most of the money himself) because there is no way I'd ask someone else to take responsibility for a child that couldn't/wouldn't take any responsibility for themself.