K.B.
Don't forget to ask all the parents what they'd like to be called! Some don't like the grandpa/granny terms, and go with nanna or poppy. My parents wanted to be called Grandpop and Grandma, but all the kids had a different idea and now they are Gammy and PopPop. My in-laws were Oma and Opa (German) and when Oma died and Opa remarried, we asked her to choose another name so the kids could remember Oma Mary, and she chose Nanna.