That confession from the teacher means any libel case is immediately done for in any sane court. Swedish ones though?

I bet if the poor girl was persuaded to complete the assignment, and wrote about the muslim voicing horror at the awfulness of islam, and wishing for an escape, she would have been punished by the school. So the way it turned out seems like the best that could have happened, hopefully the parents pressure the school to fire the teacher responsible, or threaten to withhold funding if they refuse.

If you hate a kid blabbing to their parents about how shit your schools and classrooms are, then improve them. Problem solved.