So, I reread Magic for Marigold and then read The Coming Storm (set in P.E.I. in the mid 20th century) by a modern Canadian author. The former book used “mum” (L.M. Montgomery characters usually use “mother,” otherwise they use “mum”). The latter book used “mom.” I feel like I’ve only heard Canadians Youtubers* say “mom.”
I was wondering when the switch occurred, but maybe there wasn’t one? Here is an article (I couldn’t find any more linguistic site) mentioning the usage of “mum,” “mom,”** and “mam.”
In my searches, I discovered also apparently some places of England use “mom”?!
I knew about “mam,”*** for Ireland, but I thought maybe it was an older form or regional (I noticed that Hoil, Arms, and Hog use “mum” in their sketches). I know JK Rowling had Seamus using “mam” in Harry Potter, but she started writing in the 90’s.
*And all the Hallmark (a Canadian company) movies which while filled with Canadian actors and filmed in Canada are typically set in the U.S. The only other Canadian I know for certain I’ve met IRL was a professor (with the most stereotypically Canadian accent ever: “sore-y” and “to-moor-row”. . . which is that regional?) who I don’t think had any occasion during any lecture to use either “mum” or “mom.”
**Also, “mom” looks logically like it comes from “mother,” but no one pronounces the “o” in “mother” like we do in “mom” (“mahm”). We say “muhther” not “mahther.”
***When we went to Holland, Michigan, with the host family’s Michigan accent we heard “mom” that leaned toward “mam.” And “downtown” was more like “donton.”