You can be sure there will be plenty of shore tours kids will like - but there aren't cheap in Alaska.
Dog sledding on top of a glacier (about $300 per person, but unforgettable).
Whale watching in Juneau (not so expensive, maybe $50 person)
There are also MANY independent tour operators in every port of call - so you don't have to use Disney's tous. You are still in the US after all....