Growing up, my maternal grandparents were Big Grandma and Little Grandma (great-grandma). My paternal grandmother was referred to by our last name. Some dear friends of the family were also Grandpa & Grandma (last name). As an adult, I discovered many of my aunts, uncles, cousins and grandparents didn't share a drop of blood-only love and acceptance. Some of these people were so dear, they truly treated me as well as their own family. To me, it's all about who loves you, not whose DNA you share. I think it's wonderful you're accepting the baby as your own.