I know it sounds trite but, there is more to this business than what goes on in High School. Actors will often move out of a town, find a new agent, reinvent themselves to get jobs. I know actors who can't get a call-back at certain regional theaters even though they did the show on Broadway. (yes, not even a call back) So how does this help your dd?
Let her know that this (unfortunately) happens. It's not her fault. If when she auditions she is well prepared, takes risks and does her absolute best, she's done her job. If they don't cast her, it their fault, not hers. She should keep up her training and be ready for the next audition in or out of High School.
The other rout you could take is the drama volunteer. Selling tickets, helping with publicity, raising money are things that will get you in front of the teachers in a positive light, maybe breaking down any walls that you or the teacher may have put up. Teaching High School is tough. Decisions made are almost always 2nd and 3rd guessed. Keep positive and you may gain some insight as to why decisions are made the way they are