My mother has been a widow for 2 years now, after having taken care of my father who was ill for 8 years. She's very fit, however, she doesn't get out because she no longer drives, and thus has to rely on her family. With today's busy schedules, we don't get to do that on a regular basis. Check out activities and classes , and day care centers .
Some groups do provide transportation, so ask.
Perhaps you will meet someone dropping off her own mom or dad at one of the activities and you can arrange to take turns.