Grandma alternatives?!!

Leanne
My mom doesn't want to be called Grandma, what are some other names she could be called?
I call my dads parents Grandma&Grandpa, my moms Mom is Gram, I think my dad is okay with being called grandpa, my mom wants to be called nanny or nana, idk I don't like it! My fiancés parents will be Oma & Opa I'm sure.