After Chris—who has lost his memory in battle during WWI and forgotten about his marriage to Kitty—demands to see his former love, Margaret, Jenny goes to fetch her. Jenny explains that Kitty is aware of Chris's love for Margaret and is still willing to facilitate their meeting. Margaret, who cannot explain the situation to her own husband, responds by saying:
“Oh! [...] She must have a lovely nature!”
This is an example of situational and dramatic irony. Margaret interprets Kitty's behavior as evidence of her selflessness. In fact, Kitty, who has already derided Margaret to her face and behind her back, hates her. Readers know this, but Margaret does not. Knowing that poverty and hard work have eroded Margaret's beauty, Kitty is cynically betting that Chris will desert her once he sees how she's aged. Her willingness to arrange the meeting thus testifies to her narcissistic nature. The situational irony lies in the fact that Margaret has drastically misinterpreted Kitty's motivations. The dramatic irony lies in the fact that while Margaret is in the dark, Jenny and the reader understand Kitty's motivations all too well.
The credulousness Margaret displays here might easily seem silly or gullible in another character. But her optimistic assumptions about Kitty's behavior actually display her own innate goodness and selflessness, qualities that distinguish her from Chris's wife and force Jenny to reevaluate her beliefs about love and class. Ultimately, this moment of irony is part of Jenny's broader emotional transformation over the course of the novel.
When Dr. Gilbert Anderson, a psychiatrist, comes to Baldry Court to examine Chris, Jenny uses verbal irony to describe the welcome Kitty gives him. As a married woman of the upper class, Kitty looks down on middle-class professionals like Dr. Anderson. Nevertheless, she makes sure to dress and behave attractively when he visits. Jenny says that beautiful women of Kitty's class behave this way because:
[...] they are obscurely aware that it is their civilizing mission to flash the jewel of their beauty before all men, so that they shall desire it and work to get the wealth to buy it [...]. There is, you know, really room for all of us; we each have our peculiar use.
This passage, especially Jenny's sly assertion that "we each have our peculiar use," is an example of verbal irony because she means exactly the opposite of what she is saying. Jenny does not actually believe that Kitty's vanity is a commendable trait or a means of serving the broader society. In fact, she's highlighting the fact that Kitty's snobbery, demonstrated by her lack of genuine regard for men like Dr. Anderson, can only be overcome by her personal pride and need for admiration. The elevated narrative register displayed in phrases like "civilizing mission" combines with the Jenny's biting tone to point out Kitty's worst characteristics in a passage that seems to be praising her.
It's important to note that at the beginning of the novel, Jenny seemed to uncritically admire Kitty and to genuinely believe that her beauty had a "peculiar use." By carefully tending to her appearance and home, Jenny initially suggests, Kitty is both creating a serene domestic atmosphere for Chris and fulfilling the standards of behavior for women of her class, thus serving a broader social purpose. By this point in the novel, Jenny has come to value and envy the authenticity of Chris and Margaret's love affair, and she has come to see that Kitty's relationships are hollow and superficial by contrast. That Jenny ironically states an argument she might earlier have put forward sincerely emphasizes the mental transformation she has experienced over the course of the novel.
