Are either of these two hotels family friendly. My husband will be attending a convention in May and we (me and my 3 year old) may want to tag along and explore Miami.

I've read about the Zoo and Aquarium. Are there any other family activities you would recommend?

Your thoughts would be appreciated.

Fountainbleu is to be avoided in my book. Huge, soulless, bad service, average rooms, packed with conventioneers.
Loews is definitely worth a look...new since I last visited, I believe.

I have stayed in both. On a scale of 1 to 10 I'd rate the Fountainbleau at about 2.5 and Loew's at about 9.8. We had a certificate for Loew's and got upgraded to the club level which was especially nice, but even without the upgrade the Loew's is far superior. It is also more convenient for walking to Lincoln Road area (very close) and all the places of South Beach. Fountainbleau is considerably further north. There were a fair number of kids at Loew's, and I was aware of seeing some sort of program going on out by the pool, kids with a staff member doing "art" projects.
I will repeat my favorite story about the Fountainbleau. One time we were there for three days. When we checked in there was a discarded room service tray of half-eaten food on the hall floor in front of the room next to us. When we checked out, it was still there!

Ditto the others. We stayed at the Fontainebleau this past December. Sorry we did. I'd have rather spent that considerable amount of money staying in the south beach area.
H

Loews is a great hotel, well located. Stayed their last June with a convention, but even then the convention crowd was not an issue. The pool is wonderful, and you are right on the ocean. Yes they have kids activities for a mimimal cost. My 7 year old had great fun. Restaurants at hotel are pricey, but good fun is abundant within a 10 minute walk.