Yaay! I'm a young grandma, too. It's the BEST.
You know what it was like when you were a parent in the mall, a small voice would call out "Mommy" (or in your case Daddy), and your head would swivel....
This is so much BETTER. My head swivels for that small voice crying, "Grandma!". We ADORE each other. We CONFIDE in each other. We PLAY together (except for Bratz. I am deathly bored of dolls). All the tough stuff I leave to mom.