i'm so sorry your daughter has to go through this.. i know it's not an easy thing for EITHER of you to be put in that position!!
maybe talk to someone
HIGHER UP?? 
i'm not much help, sorry.. but something needs to be done for sure. whether its talking with the teacher or someone else there that can help you.. your daughter deserves the best, especially since you are paying good money to support her passion!! she has a talent and has been given an opportunity to express her creativity, with the possibility of pursuing it professionally.. her dreams/goals should not be affected in any way by one person's negativity.. her teachers should be mentors for her(especially at a school that you choose to send her to) It very well could be the way the teacher is..(you know some people just aren't very compassionate and come off rude, etc. maybe before you approach a higher up.. maybe you can introduce yourself to her, so she sees how much you care about your daughter and her passion! then see how it goes from there, if nothing improves THEN say something to her or someone above her?!