December in Florida

[Terribletwoos]

We are flying in and out of Miami and are looking for the warmest and most family friendly places to stay. Three adults (myself, DH, my adult niece, our two year old and a 3 month old).

We are going for 3 weeks and Miami and Orlando are booked. I'm looking for a one week excursion to a warmish beach. A resort with babysitters would be great. Or an airbnb with a heated pool and near a beach.

So far I have narrowed it down to:
Naples
Somewhere along the Keys
Fly an hour to Nassau

Cayman is an hours flight from Miami and it's still 26oc-27oc here and sea still relatively warm.
No all inclusive hotels but plenty of beach rentals on VRBO and many babysitters available. Stay on northern end of seven mile beach for the best stretches of sand, the beach on southern end has eroded so no beach, just sea.

Thanks! will have a look, didn't consider cayman.

It's very expensive here and you'll be coming at the peak of season so may not fit a budget, but most certainly family friendly!
If not, recommend an AI resort in Jamaica or Mexico. Both are approx 1 hour from Miami