I saw your post. Where are you based and what are your mother's interests? My parents moved to London about six years ago - they're now 80/late 70s - it's a tricky area because of all the young professionals. I looked up to find various social events for my mother (my father is happy being a hermit
). NADFAS operate in London - but the nearest one is Kensington so I ruled that out as my mother couldn't get there - but yours could if she was interested and/or they may have a closer branch.
The libraries run various Adult courses/lectures - but the content wasn't anything my mother would have fancied.
I have been unable to find exercise and or tai chi type things for adults. There's a volunteer website called www.do-it.org.uk
which has all manner of things you could think of. Most required a continuous commitment and my parents were at that stage back and forth to France.
If she's interested in volunteering The Trinity Hospice is an extremely worthwhile cause and I believe they have allsorts of opportunities.
I'm sure my mother would love to go for a walk/catch up with your mother - but she's rather slow walking these days - she probably wants someone faster
Let me know interests and I'll see if anything springs to mind.