for me at 49 there are three camps in my friends:-
one is the ones who never wanted to have DC and have no regrets, they either have nephews, nieces, godchildren etc
the second camp is they've not met the right person to have DC with or have been married (like me, now divorced), pregnant and had miscarriage/termination etc - so not right time and now time has run out.
Third camp - TTC but never happened.
Me - I'm more in second camp - a lot of relatives were 'in second or third marriages with or without children'. My DM though divorced was a single mother and in 70s this was a stigma. Then best friend got pregnant at 18 and regretted it as she told me - another best friend got pregnant at 24 did better. I just never met the right person or ran away from the semi right person (including my ex-DH) - I did want DC but then I didn't want DC - I was very 50/50 about it. I had the hormones jumping, clock ticking 30s/40s and wanted DC but then I realised my life, finances etc would never be the same again.
Hard to put into words. If I'd really wanted DC I think I'd have frozen eggs or just had DC.
I do have a nephew, young (2 years old) whereas another close friend has no nephews/nieces (she has 2 siblings who for various reasons don't have DC) and was worried about leaving her DP with no grandchildren and also no-one around for her - she has met a man who has DC so potentially she could be a stepmum.