This is a sore spot for me; a raw wound.
I loved my grandmother very much and called her Nana (pronounced nah nah). She died in 75, and I looked forward to being called Nana when my turn came.
When my ds and dil had their first child, I was called Nana, and loved it. When my eldest grandson was four and my youngest grandson was one, my ds and dil exploited my mother's dementia to gain $$$, and moved her out of state without telling anyone where they were, then dumped her two years later - I found out that they encouraged my grandchildren to call her Nana, and I actually found a letter from my ds to my dm telling her that *she* was the only Nana. He insinuated that he was rejecting me in his letter (to gain her cooperation I think), and this was when he and dil were pretending to have a relationship with me - they did not tell me any of this and had not had a relationship with my mother for five years (long story-she insulted dil on her wedding day). I'm trying to make this short but just to say that the name is gone to me now. If my dds have children, I think I will go with the flow and will withhold my two cents. I don't care what they call me as long as they love me and allow me to love them.
Not so sweet a story but one I have to live with. Sorry if it is vague or abstract.