I'm 59 and on both sites under different names. I feel more at home on this site, but admit that it gets a bit dull at times for me. Perhaps because of the time difference, and I usually go straight to Active topics, so get a lot of games which I ignore. Most of the heated debates are put to bed by the time I can read them.
Some of the mumsnet topics are definitely entertaining, but I don't have much to contribute. I am learning some new language...
Years ago we had a Canadian women's forum but it was closed because it got too big and hard to manage. It was run by a magazine, and they felt like they were losing their focus. I really miss it, and as much as I love GN, I feel a bit misplaced at times. I can read but cannot comment on politics, etc. I have learned quite a bit though (better understanding of Brexit), and often will look up locations mentioned here in the good morning thread.
I haven't seen the OP reply... and you don't say really what demographic you fit into. I think GN is a fairly good mix of all decades over 50, but the retired members have more time to comment so perhaps are more dominant.