It will be me, DH, DS16, DD7. Maui is mandatory since DH has never been to Hawaii. For the other island I am thinking the Big Island would be great as its the only one besides Molokai that I haven't been to. But is there a week's worth of stuff to do there, or should I do 10 days Maui/4 Big Island?
And to be honest I don't remember Kauai very well except that its really green. Would it be better for a 7 year old?