Does this mean you are sailing out of Galveston on the 7 night including Christmas Day ? Those ports are Nassau,
Castaway Cay and Key West, is that yours ? What is the makeup of your traveling family ?
I would suggest that if you are doing an excursion in Nassau use
DCL. Check out the Port Adventures under things to do and find something that sounds really good to you. On Castaway Cay, lots to do planned or unplanned. Snorkel the lagoon, swim, Pelican Plunge, Biking, billiards, ping-pong, other games in "da shade hut," beach, and lots to eat. If you are looking for greater activity they also have excursions on the port adventure site; parasailing, kayaking, sting ray encounter, fishing, jet bike, again, up to you. In Key West it is very easy to do a number of things on your own like the Conch Train tour around the City, Trolley Tour (hop on hop off), or walk on your own. There is a lot in the area of the ship dock and you can walk to Southernmost Point, Truman Little Whitehouse, Hemmingway House, Duvall Street, Mallory Square, again it is whatever may interest your family.
The shows on the ship are great and you will have the new Frozen, I would not miss any of the production shows. If you are brunch people, then a brunch at Palo is always good, adults only. Bring a couple of different color highlighters and when you receive your Navigator each evening go through it and highlight the different things people want to do. If you pressure yourself to do everything and run from one activity to the next it is less relaxing, enjoy what you wish and don't forget to include some down time. Again, not knowing what "family" is, hard to breakdown clubs or activities, but if you do have kids, the clubs have always been great experiences for our DD's.
Most importantly, when checking in on line, sign up for as much as you can get out of the way there. Then when waiting in Port to board, read the navigator and see where Aboard you are to go and sign up for the other things you need to sign up for. These are things like certain character meet and greet, Palo, extra excursions, tastings, tours (if offered) and so on.