The novel explores the complex dynamics of families by primarily focusing on the relationship between the sisters, Chloe and Nicky. The siblings’ estrangement, caused by jealousy, resentment, and betrayal, is central to the psychological depth of the story. By depicting the sisters’ forced reunion and confrontation of old emotional wounds, Burke conveys how love, loyalty, rivalry, and animosity can coexist within a single familial bond.

The dynamic of the Macintosh sisters’ relationship is embodied in the representation of Chloe as the “better sister.” The high-achieving younger sibling is known for her discipline and self-control. By contrast, Nicky is depicted as the rebellious and impulsive older sibling, whose life has been marked by instability, addiction, and failed relationships. Their opposing personality traits and life choices put them at odds with each other. Burke uses the concept of Chloe as the “good” sister and Nicky as the “bad” to illustrate how familial roles are often defined in childhood and become fixed over time, even when people change. From the beginning of the novel, Chloe’s judgmental tone when describing her sister demonstrates her assumption that “Nicky [is] still a problem” (33). Meanwhile, Nicky’s reference to her sister as “Saint Chloe” conveys her perception of her sister as sanctimonious.

An intensifying factor in the tension between the sisters is their shared connection with Adam and Ethan. Chloe not only usurps Nicky as Adam’s wife and Ethan’s mother but also helps Adam to gain sole custody of his son. Chloe’s acknowledgment that she chose Adam and Ethan “over the rest of my family” conveys the magnitude of this disloyalty and the protagonist’s suppressed guilt (6). A further source of conflict for the sisters is their contrasting feelings about their parents. Burke illustrates how siblings growing up in the same household can have different recollections and experiences through Nicky and Chloe’s differing recollections of their father’s alcohol use disorder and the violent abuse he inflicted on their mother. The author suggests that Chloe’s perception of her father as loving and fun stems partly from being sheltered from the worst of his violence, and partly from the selectivity of memory.

However, the evolving relationship of the Macintosh sisters through the narrative illustrates the depth of familial bonds, even when they seem irreparably fractured. Adam’s murder and Ethan’s arrest mark a turning point, forcing the two women to reconnect. As their shared determination to protect Ethan prompts them to form an uneasy alliance, the sisters reexamine the choices that pulled them apart and “stop repeating the same old patterns” that led to their estrangement (209). Chloe begins to see the depth of her sister’s love for Ethan, while Nicky recognizes that Chloe’s tightly controlled exterior masks insecurities and fears. From reluctantly tolerating Nicky’s reappearance in her life, Chloe progresses to appreciating her sister’s attributes and embracing her presence.

Chloe and Nicky’s journey from rivals to allies gives the novel its emotional weight. Burke offers a nuanced portrait of sisterhood, demonstrating how even frayed family ties retain a profound, unspoken pull. The Better Sister captures the raw, often contradictory emotions that define familial relationships, illustrating how they can be a source of conflict and pain while also offering love, support, and a lifelong sense of connection.