Hi Rachel!
Thanks for your question.
Disney's Animal Kingdom takes you on a wonderful journey of nature in various continents (Africa, Asia), a trip back in time (Dinoland U.S.A.), and a trip into pure, wondrous imagination (Pandora - The World of Avatar). Not to mention other speculator areas, such as Discovery Island and Oasis.
I would say for your little Mousketeers with the shorter legs, allow for 15 minutes between areas. If congestion is pretty low, and you can speed walk, you could likely make it in 10 minutes from Africa to Asia. However, add an extra 5 minutes so your children won't tire out quickly, not to mention enroute between areas, there's no telling what magic (or Disney character) will catch their eye to where they wish to stop and have a look-see. :-) 15 minutes in between each area at
Animal Kingdom sounds like a reasonable time.
Have a magical time at
Animal Kingdom and
Disney!
Terry