Walk with mom and her friends.
They've been getting together on Sundays since the 1970s. Back then, it was a running group of several dozen people. The host for the week would plan routes, leave water to drink at strategic points, and offer their home as post-run gathering spot. When the last person got back from their run, the first bite of potluck could be eaten. Now it's the same except the pace is a walk, because the members are 70ish to 80something years of age, and there's not quite as many people - maybe 20 at the potluck, and the potluck part only happens on weeks someone is ready to host. I ran with the group as a child, and later for a year or two after college, so now it's one of the best parts of "home".
It's not free, because the homes are spread out so we usually drive there, and you need to contribute to the potluck. But in return you get exercise, community, information, and a great meal.