When describing her relationship with James, Adelaide, and Ellen to Mr. Frankland, Mrs. McPherson articulates a paradox:
"I have no children, Mr. Frankland. I have two daughters and a son. These three grown persons here, grown up, married, having children of their own—or ought to have—were my children. I did my duty by them, and they did their duty by me—and would yet, no doubt.” The tone changed suddenly. “But they don’t have to. I’m tired of duty.”
What Mrs. McPherson means by this statement is that while she does have grown offspring, "two daughters and a son," they are no longer her "children" in the sense of needing her care and guidance. They are adults with their own lives and their own families. She makes it clear that she knows James, Ellen, and Adelaide are only visiting out of duty, that she believes they did their duty when they were younger, and that she knows she did so herself. Now, however, things are different.
Her argument here is that just because they are her biological children doesn't mean the members of her family have the same responsibilities to each other that they once did. She points out that their roles have changed; they used to depend on her, but now they expect her to depend on them when she doesn’t want to. The paradoxical use of the word "children" here plays on its double meaning: as the widow’s offspring and as people who depend on her. It's a clever way of saying that the parent-child relationship has evolved, and that Mrs. McPherson intends to disrupt it even further.
