I know the short answer is not let her go to them but it gets awkward explaining why she doesn't want to. Trouble is she just doesn't enjoy them very much - she hates the lack of sleep, the girly bitchiness and silliness that can happen and is generally not keen. I can see her point - the odd time we've had friends to stay here they are a complete pain and nobody ends up having a decent night, but I don't know whether I should put that aside and encourage her to go along with what others seem to enjoy.
Any other girls who don't love sleepovers?