There's a bunch of us "older" moms. I prefer to see it as a seasoned adult who decided to enjoy the miracle of children...or else, as my cousin put it, I'm an old fart who was having more fun than expected.
Check out p.2 or the 40-somethings thread. There are a group of us who checked in on a similar thread "Anyone here 40-plus with Pre-schoolers?"
I've got a 3 yo. I love being a mom at this age. I'm more laid back now than I was when I was in my 20s or early thirties. I can understand wanting to "relax and not be so involved" in a child's life at this age, but for me personnally, it's definitely better this way.
I get asked the "grandma" question sometimes and just grin. It's actually kinda fun to see people get uncomfortable because they're afraid they've offended me over my age. (It sure beats offending me over my weight!) I've also been asked if I adopted. (I've given the "I've got the C-section scar to prove it" response much to the asker's chagrin.) It all makes me laugh - probably because for once it's not me putting my foot in my mouth!
I think it's great to have kids whenever a person can enjoy them, 20 or 50.