I always called my mother "Mommy". When I was a teenager I thought that sounded babyish until the day I heard my Grandma refer to her mother as "Mommy". I called my mother "Mommy" until the day she died.
My three grown daughters all call me Moma, my spelling. The all have their own way of spelling it so when I sign, I use my way of combining. I used Grandma for both grandmothers. My grandkids use Mas, Masy, Grandma, or Grammy. None were ever allowed to address me by my name, Phyllis! We think Mas originated from the oldest grandchild going to "grandmas".