Warn her of the dangers on MSN and other chat rooms.
Older men have been known to go on their pretending to be young girls or young boys.
They ask questions like what color school uniform to you wear (to try to narrow down which school they go to).
They also suggest they get a web cam and ask them to pose provocatively.
I am not saying it is all like this, but tell her not to give away any personal details (where she lives, address, phone number, school etc).
And NEVER meet anybody.