For a moment Archer fancied that Mr. Letterblair must have told her of his coming; but the irrelevance of her next remark made him change his mind.
She broke off, still twinkling at him, and asked, with the casual irrelevance of old age: "Now, why in the world didn’t you marry my little Ellen?"
But now it was the Welland house, and the life he was expected to lead in it, that had become unreal and irrelevant, and the brief scene on the shore, when he had stood irresolute, halfway down the bank, was as close to him as the blood in his veins.
There are no more uses of "irrelevant" in the book.
Show samples from other sources
The sentence should be deleted because it introduces information that is irrelevant to the passage.
The writer should deleted the sentence because it provides background information that is irrelevant to the paragraph.