I have two daughters who have tried many things. Ballet is not for everyone, and it does require a lot of discipline.

Perhaps she would enjoy dancing, but in a different way, such as jazz, hip-hop, or something else?

However, I do think you need to try to get her to explain to you the aspect of ballet that isn't her thing. Is it too slow? Does she not enjoy the movements and just wants to shimmy and shake around? Once you understand her why it will be easier for you to make a decision.