Are you looking for a character meal? 1900 Park Fare is dinner with Cinderella and friends -- "Regulars include Cinderella, Prince Charming, Lady Tremaine, Anastasia and Drizella" -- and that would be fun for little girls. My niece loved it

Little boys would probably enjoy Chef Mickey's or Crystal Palace (Winnie the Pooh characters) more.
Are you planning to be in one particular park that day? That can make a difference as to what place you choose, what would be most convenient. For example, if you are going to be in MK, then Crystal Palace would be very easy to get to. Or if you will be in AK that day, Tusker House or Boma at the AKL would be much closer.
Also, do the adults in the group have adventurous tastes, or do they prefer simpler, more familiar food? Boma and Tusker House have an African/East Indian influence, and some people love it (like me

) and some don't

Biergarten in Epcot is German food (obviously), and some people love that -- I'm not wild about a lot of the ingredients, but the show sounds like fun. From your signature, looks like you'll be at SOG, and they have their own buffet, Garden Gallery, with different "theme nights".
Lots of choices!