In Ann-Marie MacDonald's multigenerational saga Fall on Your Knees, Mrs. MacIsaac is the wife of the store owner (Mr. MacIsaac). James Piper, the father in the story, visits MacIsaac's store for provisions, though he does not want to speak to many people in town (as they shun him for being a scab and working during a strike).
When James visits MacIsaac's store on page 57, MacIsaac asks him about his wife, Materia, who plays the piano. James does not appreciate Materia's talents, and he is very angry when MacIsaac asks after his daughter, Kathleen (as James is very protective of her, to the point of obsession). MacIsaac and his wife do not have any children. When James leaves the store, Mrs. MacIsaac says, "We shouldn't let Piper set foot in here" (page 58). She does not like him because he is a scab. MacIsaac, however, tolerates James because he does not want to punish James's family for the mistakes that James has made. Later, on page 69, Mrs. MacIsaac worries about Materia, who is very pregnant and heading to church with her two children. She worries that Materia is too religious. Later on page 283, the reader learns that Mrs. MacIsaac has died and that many people are surprised that Mr. MacIsaac hasn't, as he has a drinking problem. He goes on to live a long life after giving up drinking.