We had a player on our team this past season who was playing one age up. Unfortunately for her, she did not get a lot of court time, so everything ended up in frustration for her entire family.
Mojo is sending you the signal that your DD is better than their 12s, so she could fit in better with their 13s. VAE pretty much tells you that your DD is not at the level of their 13s, but she could fit in with their 12s. Now you tell me which is the better club.