Di,

My kids DID have three grandmothers:
One each from their birth father's parents, Steve's parents, and MY parents.

But it got much more complicated than that:

MY parents divorced when I was pregnant with my son, so they've been through TWO new step-grandmas who were married to "Grandpa Rolf," and one new step-grandpa when my mother eventually remarried.

NOT TO MENTION that Steve's mother died a year after we were married, and Grandpa Jim remarried. Arletta, his second wife - and now his widow - is only slightly older than I am - and she's Black.

It's all worked out fine. We just explained things as they happened. some of the "ex's" have disappeared from our lives, but not all of them.

There was a full table of grandparents at our daughter's wedding reception. If I recall correctly, Jen was represented by FOUR grandmothers - and one grandfather...

Just go with the flow. Kids aren't judgmental about things like that. (When they were young, my kids just saw it as more opportunities for presents at birthdays...)