Jennie is John’s sister, and she serves as the housekeeper for the family while the narrator undergoes the rest cure. Although the narrator’s point of view shapes the depictions of Jennie’s character, her pleasant and caring demeanor comes across from the first moment she appears in the story. She enthusiastically steps into a caretaker role, generously providing for a family that is not directly her own. Given this initial introduction, the narrator’s subsequent assessment that Jennie has “hopes for no better profession” implies that her sister-in-law readily accepts the social structure and gender politics of their era. A life within the home is enough, it seems, for Jennie, unlike the narrator who subconsciously feels trapped by the limits of domesticity.

Despite this internalization of the Victorian era’s patriarchal values, Jennie is less aggressive than her brother, John, when it comes to attempting to impose those values on others. John, as both the man of the house and the narrator’s physician, draws on his inherent sense of authority whenever he tries to get his wife to act or think in a certain way, often infantilizing her in the process. As a woman, however, Jennie can better sympathize with the narrator’s situation and is often “good” to her, respecting her wishes and leaving her alone when asked. This dynamic, along with the fact that John is often gone from the house, allows Jennie to maintain a closer degree of contact with the narrator as her mental state shifts. Towards the end of the story, the narrator feels increasingly threatened by her presence and care, fearing that she may be trying to understand the wallpaper as well. Even still, she does not expose Jennie to the same chaos that John discovers at the end, thus suggesting that she is the lesser of two evils.