Would you let your 12 year old..?

It really depends on how she feels. If she really wants to go and will not be homesick, then I think she would have a great experience. If she isn't sure, then don't send her. It would be very hard on her to have to be alone for two weeks if she isn't sure she wants to be there. If you really want your daughter have a great experience, maybe tell her that she will have a great time and will love it. If you can get internet service on the boat (I'm not sure if you can) maybe send her with a laptop, so you two can IM or video chat to stay in touch while she's away. I hope I helped!!