As a teacher I would much rather know! I'd hate for one of my mums to be worrying about something and me not knowing about it. Just be open and honest...that you don't want to be 'difficult' etc...ask for advice...'is there something DD could do to help the situation'...oh...make a time too so you're not catching the teacher at a bad time...it's much easier when we have time put aside to have an uninterrupted conversation! Good luck