Summary
The speaker now addresses someone named Cousin Kate. She recalls that Kate became the more beautiful of the two, so that the lord, catching sight of Kate at her father's home, took notice. Upon falling for Kate, the lord rejected the speaker, obsessively watching Kate as she worked in the fields or walked through town. Eventually he took Kate from her humble origins into his luxurious household, marrying her as a reward for her perceived purity and goodness, and thereby increasing her reputation for being pure, good, and beautiful. Meanwhile, the speaker, who is treated as a sexual object by the lord, is treated derisively by neighbors and has neither the material wealth nor the emotional validation Kate does. The speaker, perhaps expressing anger at Kate, asks her who between the two of them truly has a tenderer heart. Kate, she concedes, certainly has a "stronger wing"—a greater capacity to survive and move through the world freely, or at least more luck in doing so.
Analysis
The first two stanzas of the poem offered a relatively simple conflict between two characters. There, the speaker laid out the history of her relationship to the lord, moving from attraction and interest to rejection and exploitation. That alone was a substantial narrative, in which the lord's cruelty offered the speaker hope before ultimately making her life far harder than ever before. But here, Rossetti completely shifts the narrative, making it clear that the real conflict is not between the speaker and the lord but between the speaker and her cousin. In these two middle stanzas, our cast dramatically expands. The lord becomes part of an ensemble, which includes the wider community of which the speaker is part. This ensemble both observes and shapes the troubled relationship between Kate and the speaker.
The speaker undoubtedly envies and resents her cousin. This is in some ways a much worse situation than one in which she merely feels rejected and used by the powerful lord, since he has evidently managed to turn her against a member of her own family, sowing disharmony in relationships far beyond his own. At the same time, the speaker feels more than simple envy for Kate's new lifestyle. Her feelings take on a new sheen because of the irony at the heart of the two girls' fates. Kate has received the lord's favor, and all the advantages that come with it, precisely because she is considered purer than and morally superior to the speaker. Indeed, even the word "fair," which the speaker applies particularly to Kate, seems like a pun here, meaning not just "beautiful" but also "just." However, Kate's insulated life with the lord comes at a cost to the speaker and requires Kate to withhold compassion from her miserable cousin. Therefore, the speaker asks, can Kate really be considered fair or good? An additional layer of irony comes into play as a result of the speaker's exploited status. Forced into a kind of sexual servitude as a result of being deemed less pure and good, the speaker is now judged by others as impure and even unfeminine. Kate, drawn into the more socially accepted role of wifehood specifically because she is judged to be sexually and morally pure, is now able to maintain that reputation.
These elements of the situation are deeply ironic and paradoxical: first, Kate's (perceived) moral superiority unexpectedly puts her in the position of oppressor, and second, the speaker's punishment for being seen as inferior is to be forced into a position that makes her even more so, at least in the eyes of her neighbors. A final layer of irony tops it all off. The speaker, despite her anger at her cousin for joining forces with the lord, seems not to consider that she, too, once hoped to be in Kate's position and to ally herself with this callous, almost omnipotent figure. This desire for power and comfort is understandable, but her anger at Kate makes her seem somewhat unreliable and lacking in self-awareness. This doesn't mean that she isn't sympathetic. It does, however, mean that her characterization is subtler than she herself seems to realize. Rather than being only an exploited victim, she is an exploited victim who would likely exploit others if she were able. This makes Kate and the speaker, despite the tensions between them, more similar than the speaker seems to realize: they are divided by the whims of circumstance rather than by fundamental differences in morality or values.