Being a single working mom, holding down 2 jobs for most of my 2 DS teen years, I had to learn to trust them to be able to handle themselves alone. And although they did some stuff together most of it was with their own set of friends. They used public transportation to go to the mall, movies, store, and friends houses. This was before cell phones were in every pocket, so most of the time they checked in with me before going out.
Anyway, the first time they went out on their own at WDW I really didn’t worry, they had been there many times and knew their way around, and we had check in times. I was the lonely one. WDW is no fun alone! I actually saw them many times that day (but they didn’t see me), they hooked up with some girls (which would not have been cool with mom around) and met me at the specified time (and asked for money).
After that, there was no turning back. Once we hit the resort, they were off, sometimes together, often alone. But they always seemed to show up at meal time. :glare:
So my advice is do what you are comfortable with. You don’t want to spend your day worrying.