I can't help wondering if you are trying to be too PC. Children always manage to find a fitting name for grandparents according to their expertise with pronunciation. Keep the "proper" names for the paper records. My husband and I are simply Granny and Grampa and that suits us fine. My difficulty lies in the "modern" trend of calling people by their first names when they are of an older generation. I always called my elders Mr. and Mrs. unless they were close friends of my parents and then they became Aunt and Uncle whether they were related or not. Both my sons-in-law call me by my first name and I find it offensive although I've never told them so. They both have living mothers but I called my mother-in-law Mother although my own mother was alive. It never seemed to confuse anyone! Any suggestions?