We have done this once (in 2005) and are doing it again this Jan. with the same child. The friend is 18 now, 16 when we first took her, and she has siblings too. I know the little brother is probably mad at her getting to go again. My DD's friend comes from a divorced home and her parents would never be able to take her and her siblings. The first time we paid for her plane ticket, room, and part of her food. This time she is on her own to pay for her stuff since we are staying longer (10 nights) and we have to have 2 rooms ourselves since our family is bigger and it will be a much more expensive trip all around. We discussed this up front and the parents are fine with it. I think they are thankful that their DD gets to do something they would not be able to do for her on their own. I did not get the impression that they were offended at all - I guess not since she is going with us again! I have found it to be a wonderful experience for our DD17, but I wouldnt take just anyone. It would have to be a very well behaved, polite and appreciative child for us to take them. Otherwise it could make for a miserable week (as has happened with other kids before on other trips).