WOW! Thank you all for such interesting answers!
I have a grandmother name now! I realize, as a few of you said, that a child may give a name, but I have to start with something to tell the baby and sign cards & gifts. I decided to go with a short name; Granny! He may say Ganny until the r is conquered, but he'll be unaware of it and will eventually say Granny. My girls didn't pronounce GrandmaCharlotte for awhile until all of a sudden they did. He can shorten it to Gran when he's older. Anyway, I'm so excited to be Granny! I think it sounds like a happy person!