I can only give my very personal perspective on this - my mum was your age and my siblings almost exactly the same age as your dcs when I was born.
It was much more unusual to have children older in the 70s/80s but I always felt a bit awkward that my parents were older, and I didn't have the same relationship with my siblings as my peers. My mum was often mistaken for my gran and my sister my mum.
Likewise, my dcs have a different relationship with their grandparents, aunts and uncles and cousins, who were all in their teens when my dcs were born. Everything is just a bit out of kilter in my family. It's not necessarily a bad thing - I'm close to my siblings but in a different way.
Also, my parents were too old to really help with childcare and my dcs see their grandma as a very old lady. My dad died before ds2 was born - which could happen at any age but is more likely the older you are.
My parents said that having me later kept them young, but it also meant they couldn't do the things they wanted to without children until much later.
I wouldn't necessarily say don't do it, but you really do need to think it through as the impact on your family, and especially your youngest, will be massive.