Then I think you should let her go alone. She knows that if she gets fed up, you'll support her leaving. But she isn't choosing to do that (yet) so she needs to talk it through with the school and reach her own conclusions.
It's tricky when you think they're making the wrong decision, but if this was her dream then only she can decide that it's not working out.
She can always go on her own and then if you think she didn't get all the information she needed, then you can follow up.
She may have been badly treated, it's a cutthroat kind of business in the dance world, as we both know, but I'd suggest staying calm - what's done is done and you can't change the principal's mind by shouting or get upset (I'm guessing this is a partners issue?)
(I was 'gettingalifenow' before name changing a while back, so we've chatted before)
It's Ballet school; they keep saying if she works hard they will move her up. Then they tell her she has worked hard but they won't move her up 'this time' & they've done it 5 or 6 times over the last year
Turnout is crucial in ballet as is flexibility. I would imagine the others have been doing ballet for longer & so there will be the need to "catch up"/ Not sure about 2, maybe they feel that she could learn some tips from them?
I know at my dds dance classes the "hanging around" time is often spent practising, getting people to show how to etc & maybe that is why they want more socialising? Maybe they are concerned she is feeling a bit discouraged with beinbg the eldest?