Where I live there is little chance in them waiting until they are married or even until high school! My main focus is to give her enough knowledge to protect herself from unwanted pregnancy and from sexual transferred infections and to give her enough self confidence and courage to say no when she don’t want to have sex and only have sex for the right reasons.
I try to bring about the reasons for having sex with the right person and that sex is supposed to be something positive, not something one does just to have it done or have sex just because a boyfriend wants it!
And of course I try to give her reasons to wait with sex, but I am not focusing on a certain age but until the circumstances are right for her. I also let her know she can come to me no matter what. I won’t be happy with her if she gets herself in some kind of trouble but the main thing is that she is alright. They are in the beginning of a long learning period and the longer they wait, the better, since they will get more common sense and better judgement with age.