We did Grandma/pa [last name], including for my step-father's mother, but it's more complicated for my daughter. My husband's parents have older grandchildren and had established preferences with my husband's father going by 'Papa' (which is what I call my father, just for added complication). None of my parents are local, and we do a lot with Scott's sister's in-laws as part of the group, and we had to figure out what to call them. Scott's sister's MIL just wants to be called 'Nana' the way she is by her grandchildren, but her husband wants to be 'Uncle' instead of 'Grandpa.'

My father and step-father have ended up as Grandpa [first name], mostly because I call my step-father by his first name and didn't think about it. My father was a bit disconcerted. His current wife had a title already being used by her pre-existing grandchildren, so we've gone with that. My mother is Grandma [last name] or just Grandma (since no one else is using that title).