You might also give Kona Cafe a try. It's much more peaceful than Ohana, and it's a better bet for shy kids. (My nephew freaked out over the screaming, running, goofiness of Ohana.)
One caveat for anyone taking kids to Kona -- they will swing your kids past the dessert display, and show them this completely disgusting ice cream/cotton candy thing, complete with a "Hey, wouldn't you like Mom or Dad to order this for you!" kind of pitch. It's very very unworthy of this otherwise great restaurant, so be sure to prepare your kids. (Nephew came through with a disdainful, "I don't like ice cream" before turning up his nose and walking away, lol.)