Dd (9 next week) has just had her new friend who will be in her class next year to a sleepover. Frankly I'm not at all happy. This girl is 9 going on 15. Every time I overheard a bit of their conversation this girl was talking about boys. And not in an innocent way either. "Oh, so-and-so - he's a perve." And "I'd like to tongue kiss with x" 
Dd seems rather star-struck by this girl who is almost a year older than she is. She has started to copy her mannerisms and do that shaking of shoulders with accompanying back-chat sort of thing.
I know dcs must be allowed to make and break their own friendships, but I feel quite depressed about this and wonder what I can do short of withdrawing her from school and hiding in a cave (not an option, btw!).