Good luck! I have one DGD, light of my life, the lil monster.
I know, to some being called one of the Grandma names makes them feel old. Not me. It feels old to think about having a grandchild, but I feel like a little kid when I am playing with her. I get to watch all the little kid movies, eat candy, enjoy all the toys again.
I asked to be called Granny. One of my favorite people was called that - my friend's and ex-sil's grandmother.
There is nothing like having some little person who adores you come screaming into your house, arms open for a hug yelling "GRANNY!!!!"