While Jenny is an astute observer of the social and romantic relationships around her, her unconfessed love for her cousin Chris makes her an unreliable narrator.
Jenny is an unmarried woman in her thirties who seems to live permanently with her cousin and his wife, Kitty. While this arrangement might not have been uncommon in her own era, when women rarely lived alone, the fact that Jenny doesn't acknowledge or explain it causes the reader to wonder about her motivations. Initially, Jenny seems content with her life, saying that she has admired Chris since childhood and finds meaning in helping Kitty create a beautiful and relaxing home life for him. She relates these details about her life in an open, straightforward tone that encourages the reader to trust her.
As Jenny learns about Chris's love for Margaret, cracks appear in her serene veneer that complicate her reliability as a narrator. While Jenny is not jealous of Kitty's relationship with Chris—perhaps because it's essentially loveless—her cousin's passion for Margaret upsets her deeply. Imagining the lovers strolling the grounds together, Jenny remarks that she is "physically so jealous of Margaret that it [is] making me ill." Later, her jealousy even causes fits of sobbing and despair. By the time Jenny is experiencing this emotional crisis, the reader has intuited her love for Chris through her stated jealousy and her sensual descriptions of her cousin's beauty. But while Jenny does name her feelings, she can't admit that they stem from her love for Chris—and her refusal to acknowledge this self-evident passion shows that she's not quite as dispassionate an observer as she presents herself.
Jenny's unreliability as a narrator is most apparent through her love for Chris, but as she questions her values over the course of the novel, she makes other admissions that suggest she's not quite as trustworthy as she initially seems. When the psychiatrist, Dr. Anderson, visits Baldry Court, Jenny tells him that she's always known something was wrong with Chris and Kitty's marriage—something she never acknowledged in her previously glowing accounts of life at Baldry Court. After she makes this pronouncement, she notes to herself that "a sharp movement of Kitty’s body confirmed my deep, old suspicion that she hated me." As with her suspicions about the marriage, Jenny has never acknowledged the possibility of such an enmity before. These casual revelations cause the reader to wonder what other information Jenny might be withholding.
At the beginning of the novel, Jenny is living a life that is mostly satisfactory to her—at least, she's happy enough to avoid delving into subjects that might cause her displeasure. By the end of the novel, she is forced to confront the things she's been hiding from herself, like her unrequited love for Chris. By slowly casting doubt on Jenny's reliability as the narrator, the novel forces the reader to experience a version of the emotional destabilization she is going through.
