At $31 per adult (includes the 11 year old) and $15 per kid I would probably skip 'Ohana or go by myself if the 4 others in my party only wanted nuggets and fries.
You will still be made to pay the all you can eat price. However, you can not get refills on "special" orders/options. So, you would pay full price at Ohana for fries and nuggets.
I LOVE ohana... but if they are only going to eat nuggets and fries go elsewhere. My DD ordered it and the fries were cold and there were only 4 small nuggets (like CS style). If your family isn't going to enjoy Ohana don't waste the money. There really isn't much to "experience" if you dont enjoy the food and it will cost you over $100 easy.
I agree with the others. If your family is just going to eat the fries & nuggets and not what's on the regular menu, then skip it and don't waste that much money.
We love the food and thankfully have kids who are not picky. They gobbled up the salmon I made for dinner tonight so we don't ever have a problem eating anywhere. One of the last times we ate out they ate more than half of my shrimp and scallops! Next time I'm going to make them get their own!
Go somewhere that has more options and isn't going to limit them to the family style menu or paying lots of money for the fries & nuggets. HTH!