I would not call her back; you have called her 2-3 times and the ball is in her court. She may be setting you up to not have enough time to produce a good show/have a good enough rehearsal. If the kids were not keen on rehearsing the show, sounds like they aren't going to be too hurt at there not being one, like adults are deciding things for them. If the kids had been really into it I'm sure you would have been too and then you all's energy would have blown this lady with her controlling self away.