At this point the only thing I would do is look for a ballet companion as it doesn’t look as she plan on going. And the other thing is ask for a refund. Not sure why you feel bad asking for money back. You prepaid and she is now gone and isn’t communicating. No point to tell her anything except that since she stopped communicating you need money back. In the future I’d not prepay unless it’s property documented. And there is zero need to explain anything to her about other trainers or uour plans or her actions. Waste of your energy