My daughter is lucky to see my mom a fair amount but my husband's mother lives far away, making it difficult to stay connected. It also makes it hard for me to make sure she knows she really has two grandmothers.
So I've tried really hard to be specific as to which Grandma she will be seeing or talking to, for example, my mom is Grandma K. Well, this was a tough concept for her to initially grasp so I said things like "Grandma K is the one we see all the time" and "Grandma K is the one who has the dog, Shadow."
After a pause, she asks, "Is Grandma K the one who always gives me ice cream?"
And mom, you've been busted!