We're babysitting my sister's kids and my nephew (3) calls both me and H "mama". He came looking for me and asked H "Where's your mom?"
What's funny is my nephew, my brother's son, who is 3-1/2, asked me at my parents' house, "Where's your dad?" When I asked, "You mean Grandpa?" (who was right there), he said "No, Uncle *H's name*".
Re: Do other kids do this? Too cute.