We will be staying at the Marriott Resort Kauai and the Mauna Kea on the Big Island, my wife and I and our daughter who will be 1. I'm looking for suggestions on things to do outside the resorts. We plan on spending a lot of beach and pool time, but we would like to mix it up and go tour any good nearby sights.
The Kauai Marriott Resort is very family friendly. Huge pool, adjacent to a lawn and sand lagoon front. You'll see lots of other parents and kids there. Very close by the Marriott resort is the Kilohana Ranch/Plantation, it has a train ride around the Plantation that has a stop to feed, goats, mules, pigs, etc. A rum tasting room, and we enjoyed the luau dinner show there. On site at the ranch is Gaylord's restaurant which we enjoyed both for lunch and dinner. Also, close by the Marriott is a shopping mall.
Of course, Kauai offers lots of other beautiful sites and activities all over the island. You'd have to decide what you'd want to or could do with a 1 year old in tow.