co-grandmother

plural co-grandmothers

1. the mother of one's son- or daughter-in-law, as common grandmother of their children; the relationship between women who have grandchildren in common; maternal grandmother vis-à-vis paternal grandmother.

   2 more examples

   Talk to enough grandparents and one thing becomes clear: Because she's closer to the mother of the children, the maternal grandmother generally has a slight advantage. Or, as Audrey Berson […] put it: "She's my daughter, so I have the edge." Even so, Berson's co-grandmother works in the same town as the grandkids, and she sometimes meets the bus after school. "It bothers me," Berson said. "I wish it were me."

   2009 May 19, Beth Teitell, “Horns Come Out When Grandparents Envy Each Other”, in Boston Globe, archived from the original on 03 Jun 2009, page B7

   A Canadian grandmother's essay about essentially crashing her daughter-in-law's birth […] Rhona Bennett writes of […] hopping a train to Montreal, and (in cahoots with her co-grandmother) bum-rushing the hospital […] The two bubbies called the hospital […] and naturally were rebuffed, so off they went, in search of information, affirmation, and a grandbaby.

   2008 December 2, Kate Tuttle, “A Grandmother's Right? Or Totally Obnoxious?”, in Strollerderby

   Synonyms: co-mother-in-law