I'm divorced but still in contact with my ex MiL who lives about 70 miles away. During the pandemic she became quite paranoid, losing things and convinced there were intruders coming in the house and stealing them. She had no relatives nearby and my ex, who was the only person who could realistically visit, made no effort to do so, so it was me who went to visit once visits were allowed. Both my adult children try to visit when they can, and thankfully she eventually accepted the need for anti anxiety medication and is no longer suffering the paranoia. She is however still very vulnerable, in her 90s and losing her sight. Meanwhile her other son, who lives abroad, still turns to her for financial help and advice constantly. My kids think this is shocking and that he and their dad should do more for her.
I have to assume that their upbringing by me as a single mum during their teenage years and our relationship ongoing is the reason for their feelings. Hopefully it bodes well for the future if I need their support, though I hope not to be a burden to them.
I didn't do very much for my own mum as she became more needy as I lived 200 miles away and worked, while my brother lived 3 miles away. He often complained about having to do stuff for her and said "It's all right for you being so far away" while I was the one who had the worry whenever I phoned and got no answer! Eventually the couple who did her cleaning and shopping said "if you're worried about her, phone us and we'll go and check." Soon afterwards she agreed to move into sheltered accomodation and it was a great relief all round!
Personally I think we have a duty towards the older generation, but now I'm part of that! My DS and family live 200 miles from me, and despite the distance I have visited to help with childcare on occasion, so yes, it works both ways. But as I become older I feel fairly confident that I won't be abandoned. I hope to downsize and move closer in the hope it will benefit us all.