Maybe she did have an emergency. Personally I am infuriated by the number who simply don't reply despite saying they're available.
Even if she had an emergency, she should still have the decency of dropping a quick text to let the punter know. Or alternatively, out of courtesy, message the next day apologising and offering a discount on the next booking.
Personally, if I don't get either of those from a service provider after being messed around, I do not see them ever again.