I don't know if toontown fair at the MK works the same as it does at DL, but if it does, it's a great place to meet Minnie.
At DL, mickey and minnie wait outside their houses to greet folks and get pictures before they tour the houses. At DL, if you go right when the rope drops (usually an hour after the rest of the park opens), and go straight to Minnie's house, your child can have her all to themselves (or with just a couple of other kids) for a long while, because the entire rest of the early rope-drop crowd heads straight to Mickey's place.