I always look forward to the part of my Walt Disney World vacation planning when we can start looking at the many Disney dining experiences available to enjoy. With everything from really delicious quick service meals to buffet meals that boggle the mind with the number of choices, there is something for every whim when it comes to dining.
The children's menu is meant for children ages 3 - 9 years old. You typically will never have a problem at quick service locations if you want to order a kids' meal for an adult. Table service is a bit stricter on age. Having said that, I've traveled with many picky eaters in my time. As long as you are not on the dining plan, my experience has been that even older children can get something from the children's menu. On the dining plan, adults and children over age 9 may encounter a little bit of a hurdle ordering from the kids' menu, but I have even seen with a family member that the table service restaurant was willing to get them an adult sized portion of a children's menu option. This is not a hard and fast rule, however, and would be at the discretion of the dining location.
With buffets, all you care to eat dining locations, or locations that offer a prix fixe menu, the age limit on the children's menu will be strictly enforced. Children under the age of 3 can eat for free at the buffets.
I hope this makes your planning a bit easier, and that you have a fantastic time choosing some incredible dining experiences!