shysal
In our family there were Nannys in several generations, differentiated by adding their first or last name or other title, such as Nanny Pig and Nanny Cat according to their animals. Never any confusion. I think 'Grandma' sounds more straight-laced than I wanted to be.
Yes both myself and my DiL's mother are called Nanny, with out first names added.
I wanted to be called Nanny, my mother's mum was called Nanny followed by her surname - which is actually my own first name. It makes me feel a connection to her, she died when I was just 11 and I still feel a such pang when I think of her.