Most of the RV parks around Orlando and Kissimmee are targeted toward family vacations. You don't get so much into snowbird and exclusively senior parks until south of Tampa. So focus your search on Orlando-Kississimmee and hope you can still get a booking somewhere.
Public campgrounds won't be snowbird oriented, as city, county and state parks don't usually allow long stays. But most of these park campgrounds will not have the toddler recreational facilities you seek. Weeki Wachi Springs does, but does not have a campground, you would have to find a RV park in the Spring Hill area, which is at the northern fringe of the retiree encampments.
