My mother decided that she wanted to come with us on our next family vacation. I am not at all complaining about her coming with us, and I know that it will be wonderful to have her there. My challenge is that my mother has a really hard time walking, and traveling is hard for her. Had I known that she wanted to come with us, I would have picked a different destination (like a beach resort where everything is there), but we already purchased tickets/prepaid hotel, so that wasn't an option.
This is my question: I have two very active children with a laundry list of things that they want to do. My mother already acknowledged that she won't be up for that much "adventure." I don't want my mom stuck in a hotel room the entire time, yet I want my kids to be able to cross a few things off of their wish list. My mom's proposal was that we could all meet up for a nice dinner, which, in theory sounds great, but my youngest isn't much for allowing us to relax over a nice dinner

So my question is, how much time is it fair for my mom to spend alone/how much time is it fair for my kids to hang out in the hotel with grandma. My mom will be the martyr and say "oh just go without me," but then her feelings will be hurt down the road.
Am interested in hearing how you might have balanced competing considerations on your family travels.