Actually, she was a grandmother at my age, my mom "had to get married" at 16. Had me at 20. My parents are still married and it is kind of nice to have a younger mom.
There is a woman I was in high school with who just had her 5th kid (4 different fathers) AND just became a grandmother. She also wears fake fangs and pretends to be a vampire. She seems to be proud of her "fertility" and thinks that it makes her an awesome mom.
I prefer to act old enough to be a good parent, but young enough to connect with my kids. They already have friends, kwim? Somebody has to be responsible.