I'm Grandma and my DH is Grandpa to all of our grandchildren. The greats are very little yet and we don't see them very often so they haven't chosen a name for us yet. When our DSs' stepchildren asked what to call us we told them they could call us by our first name or Grandpa and Grandma. Even the 18 year old chose GMa and GPa. He even wanted to change his last name to ours because he says our son is his real Dad even though he was 18 when they met. What a compliment to our younger son. Our older son adopted his stepson when he asked if our son could be his real Dad. Another compliment and a grand show of trust as he was about ten at the time and his biological father is still alive. Whatever they call you, grandchildren are wonderful. :)