Mickeydonald - I don't think you need to worry about the kids' menu choices at AKL. My children are older, but also picky about what they eat. We're dreading the day when DS is too old to order from a children's menu and fully expect that he'll want to serve peanut butter sandwiches & chicken nuggets at his wedding dinner.
Mara, the counter service restaurant, has a children's breakfast platter and lots of kid-friendly options like cereal, bagels, muffins and fresh fruit. At lunch and dinner they offered two kid meal options (mac & cheese or chicken fingers which I think came with a drink) but there were also hot dogs, burgers, individual pizzas and other items which would appeal to children.
Boma offers a wonderful buffet breakfast and a delicious buffet dinner. At breakfast some of the offerings have an African slant, but many are the standard scrambled eggs / sausage / bacon / pastries that you'd find on most buffets. Although they had cereals, I don't recall seeing cheerios at the buffet, in case that's a must. At dinner there are classic buffet offerings, African items, and familiar things such as pasta and chicken nuggets for children. I think Boma is a great choice for both the kids and the adults, and 2 year olds eat for free at buffet and plated all-you-can-eat restaurants at WDW.
Jiko is more of an adult restaurant, even though they have a good children's menu too. However, I would agree with Erinch that I would only take very well-behaved children there, and mine don't always quite fit that description, unfortunately. DS and DD (8 & 5 at the time) spent a few hours in Simba's Clubhouse while DH and I enjoyed a meal at Jiko.
I hope you enjoy AKL as much as we did!
