Thanks for the advice. Unfortunately, swimming is out of the question at this time since the inner harbor (need to sail 1 hour + to get out) is downright dangerous for swimming, and the water is 55 degrees still.
I want to get her more involved in getting the boat ready to go and driving. She did a good job here:
YouTube - Prepare To Tack
I'm also thinking about some "scavenger hunts" that she can do with papers that we prepare ahead. I'll think about fishing. I've never been much of a fisher myself, so that would be a whole learning curve, equipment acquisition, etc...