I'd suggest going to all character meals, based on the characters that she likes... we really haven't had a bad food experience... all the character meals we've been to have had excellent food.
We chose Hollywood & Vine character breakfast because of Little Einsteins, which my boys were in love with. They also have JoJo and Goliath there. (They're all from the newer Playhouse Disney shows that are a hit with the youngest Disney fans.) The boys got up and danced with the characters, and there were very few people there the whole time (there were actually empty tables), even though this was on a summer trip.
If she's into the princess-y things, do Akershus for breakfast (in the Norway pavillion in Epcot), which is a nice alternative to the extra pricey and hard to obtain ADR for Cinderella's Royal Table in the Castle.
If she likes Pooh and friends, do Crystal Palace... you're bound to see Pooh, Tigger, Eeyore, and Piglet... but not first thing in the morning because you want to enjoy MK before it gets crowded in late morning.
If you're looking for Mickey and friends, Ohana at the Poly or Chef Mickey's at the Contemporary may be good options.