No grand kids here and there better not be for another 20 years or more as my oldest is 5. lol
My mom and step dad are Gramma and Grampy.
My dad and step mom are Poppa and Nana Deb.
My mother and father in law are Mimi and Grandpa.
My daughter calls her father's parents Ayayo and Awowo (They're Somalian)
We call my mom's parents Granny and Papa, but the kids call Granny Grandma (Papa passed away last year...).
We call my dad's parents Grandma and Grandpa, but the kids call Grandma Nana (Grandpa passed away in '92)