Other grandparent names?

[Bathsheba]

When my DD was born she had 5 "grandmothers".

My step-mother (Nana V***) First name
My mother (Nana C***) First name
My Paternal grandmother (Nana S***) Surname
My Maternal grandmother (Nana F***) Surname
DH's mother (Nana L***) First name.

If DH's family were younger she could have had 2 more (his grandmothers!!!) But they had passed away long ago.
We put the first name of the younger nanas and the surname of the older nanas for courtesy.

There are only 3 unrelated grandfathers so we use surnames for them all.

Admittedly it took a while for the younger nanas to agree to having their first names used by our children but I think they understand the predicament and haven't mentioned any discomfort about it for about 10 years now.