I'm 62 and DH is 64 and no sign of grandchildren and it seems less likely as the years go by.
I can't believe it really, having had one child at 24 and one at 27 I never thought I might not have grandchildren at all.
I'm fairly philosophical about it (if a bit sad) as (and I know it's old fashioned) my children were my life and I'm having to embrace the advent of old age without the extra meaning grandchildren would bring to the bigger picture of life's purpose, as well as all I could share with them. It's a slight feeling of what was the point if it all? But it's ok, I didn't have my children to have grandchildren, but it would be nice.
My parents were in their 30s when they had me yet were young-ish grandparents. Some things are out of our control yet I'm still surprised how life's turning out.