I would not count out swimming in January, I was there in January and people were swimming at AOA, the pools are heated, not bath water but not frigid. Lots of little ones play in the kiddie area, and parents lounging on the loungers.
There are play ground for the kiddo's at each resort, and some offer a beach like area that the kids can play in and mom and dad and sit and relax along side of them.
You could plan a beach day - Clearwater beach is about 2 hours away with traffic on the gulf coast or Cocoa Beach is on the Atlantic coast maybe the same distance, either would be a great break in the middle of your trip for some relaxing.
You can rent a boat or go fishing, or golfing, lots of options for everyone.