You may get a few side way looks because of the kids, but as long as they aren’t shooting water guns at guests in the pool or throwing a ball around, you should be good.
As for things to do, I know my 11 year old grandaughter could spend hours working on a puzzle, loves to curl up with a good book, do a scavenger hunt, add some youth knowledge to the trivia team, eat ice cream and pizza for lunch and than go have a medium rare steak for dinner. Add a virgin strawberry daiquiri to the mix and she would be one happy kid. Funny, sounds like the same thing many of the adults enjoy doing!
Yes, you may need really review the excursions, to avoid the long boring bus trip - haha I hate them, also.
Where are you thinking of going? Good luck!