sign up for a twitter account. if she follows only the teacher, the only messages she ever receives will be the ones from school. no other temptations to get drawn into the drama.
our school has a school website. some of the teachers have facebook pages, mostly for things like Band or French Club.
Band also has text message service that allows the teacher to send one text message and it is delivered to all students and parents. They use it to update changes to the days practice schedule, tell students when it is time to head back to the bus on away trips, etc