This isn't a question about campgrounds in Florida. It's a question about a family member. Who is the family member? Are selling the TT to them? Are they borrowing it?
If it isn't my child, personally I would not loan it out. Even if it was my child, there would be conditions. Otherwise, they buy it.
If it was my child, they would probably have to buy it.
Either way I don't care what campground they park at, I don't own the TT.
Just looked at what I said above. Don't loan it. Sell to the family member. Then you don't care where it is parked.