up until i met my Dh I was not really anti children or marriage, just could not see what they would add to the fab life I was having anyway, met Dh and he added to my life, so children who did not materialise was not an issue but then was ended up having IVF after realising I had gone 5 years without contraception and yes that is possible, forgot to tke when my Mum was dying, thought what the hay! became a carer for my Dad and didn't have time to check back into my life for 5 years.
because I realised marriage had never hit my radar until DH I decided Children could be the same, and I am a real suck it and see type of person and pissed off the clinic royally as I wasn't actually that arsed if it worked or not, turned up for both egg implantations with the hangover from hell, first because it was the day after my 33 birthday second because it had taken 2 days from harvest to implantation first time, so I planned a blow out that time a full 48 hours before, loads of friends invited, rude not to, to get the call the next day! that one! we where doubly successful that time.
I would say I love my children with a vengeance, they make me sooooo happy, but I will be honest I think they are the cherry and a generous load of chocolate on the top of an amazing cake, if they where not in my life I would still have an amazing cake, but with the extras I am not willing to share a slice with anybody else with my time, my extra slices are all for me and Dh, hand off they are delish :)
So lives can change but I was ambivalent, sound like the lady in question is against, but really you don't know what she really thinks, but if she really does not want children then it could be a mess.
I have loads of intentionally childless friends (modern hippies not wanting to drain the planet, some materialistic and some not interested, they are all happy and to be honest I find them happier than those of us with children, not that we are unhappy just we have stresses they don't, I love my childless friends they keep us sane and all make allowances for us, and pour attention that only people without children, can on children.
it may work for them either way, if there is love they might be a way, all you can do as a friend is be there for them and support when needed.