I'm surprised the girl (and/or her parents) let the school take her password and such.
I wouldn't hand over my information like that to the school.
Particularly if I thought it was against my rights.
Was she going to be expelled if she didn't hand them over?
And seriously, because she said she hated someone?
When people are caught for saying things like that on Facebook at my school they just get a detention.
(They've normally been caught by their classmates printing the pages off and giving to the teachers)
And if she is having loveual conversations shouldn't they confront her personally about it and not demand for all her personal details?
I know that it's underage and all, but it's hardly going to stop them.