Impossible request!

It may be worth trying to find a marriage on FreeBMD. You could search with a wide date range. Some areas are transcribed up until the early 90's.

Our village has a 'Spotted' page on fb, maybe the area where your Mum's friend lived has one too.

Do your very best and let her know the outcome of every avenue. If her mind is still pretty good she will enjoy hearing about your efforts. Good Luck Sunseeker.

The Salvation Army have a tracing service. Very affordable £49 (I think)
Google it and the site gives you all the info on how to go about it.
It's much cheaper than any other way and very secure.

Good advice cornergran

Employ professional family historians to do it.

Sadly. like it or not, the answer is likely to be that she has died.

Why not try one of those? Send your Mum a holding message saying it may not be possible but you’ll try and not to expect a quick response. Whatever the outcome I suspect you’ll feel better if you’re honest with her, trying one of the suggested routes wouldn’t take huge amounts of time. The suggestions made to you may just have encouraged me to finally try to trace one of my bridesmaids. Last contact 49 years ago. No idea why I’d like to try. I just would .

If you're on Facebook, see if there's a page called Memories of (town/area they lived in) and join it. Then post an appeal for anyone who may know this person asking them to contact you by private message.

There's a column in the Mail on Saturdays where the track people down - you could write to them.

Yours magazine has a page for people who are looking for long lost friends/relatives. Might be worth a try.

or as "Long lost Families " to have a go

Put an ad in the local paper using their maiden names , you might be lucky