If your child won't eat off the food that is served, your waiter can get a kids meal from Kona which is next door - you have to ask for it, and some waiters will charge you just for the kids meal price from next door while others will charge the flat Ohanas price, depends on the server. They don't have any published kids menu, as the food is family style and very kid friendly.
We love Ohanas, and feel we got our moneys worth - it's a very loud, family friendly environment. I'll be honest, though we love it, I wouldn't celebrate our anniversary there, but instead choose a similarly priced nicer place. JMHO. We do love Ohanas, though =)