M.I.
I can't see the other responses for some reason, so I apologize if this has already been mentioned.
My niece goes to Shad Sisters on 51 for dance and gymnastics. I don't know how much they have, but they may be worth checking in to, especially since she's in the early part of learning. I also think there is a dance/tumbling place in South Park, on the back part of Brownsville Road, but I could be wrong.