Lavinia Herbert is one of the older pupils at Miss Minchin's Select Seminary for Young Ladies, a position that gives her considerable influence among the students. She comes from a wealthy and well-connected family, with her father having made his fortune in the oil business and maintaining ties to powerful political figures, a background that has shaped her sense of entitlement and superiority. In the anime, she is depicted with medium-length blonde hair and purple eyes, and her bearing is one of self-assured confidence, though this confidence rests on a fragile foundation of social standing and material wealth.

Lavinia is egocentric, arrogant, and deeply spiteful. She is accustomed to being the center of attention and to having her own way in all matters, so the arrival of Sara Crewe, who is richer, more intellectually gifted, and more admired by teachers and students alike, threatens her position and wounds her pride. When Sara first enters the school, Lavinia quickly loses her status as class representative and is no longer the most favored pupil in Miss Minchin's eyes, a reversal she cannot tolerate. Her resentment toward Sara is immediate and intense, and she makes no effort to conceal her hostility. She regularly mocks Sara, makes snide comments, and rallies other students to exclude her. Even after Sara loses her fortune and is forced to work as a scullery maid, Lavinia continues to taunt and belittle her, though she would never voluntarily admit that Sara still occupies her thoughts. The source of Lavinia's persistent hatred is not simply jealousy of Sara's former wealth but the fact that Sara never yields to her. No matter what Lavinia says or does, Sara refuses to be humiliated or broken, and this resilience frustrates Lavinia beyond measure.

Lavinia is no fool. She possesses a sharp, perceptive mind and is able to see through Miss Minchin's greed and hypocrisy, even as she aligns herself with the headmistress to maintain her own privileged position. She understands the social dynamics of the school and uses them to her advantage, spreading gossip, planting suspicion, and reporting on the secret meetings of Sara and her friends to Miss Minchin, hoping to get them punished. Her chief weapon is her tongue, and she wields it with precision, making cutting remarks about Ermengarde's learning difficulties or about Sara's reduced circumstances. She is manipulative, but her schemes are often transparent to those who know her well, and her cruelty springs more from insecurity than from genuine malice. Underneath her haughty exterior, Lavinia is dependent on the approval of others and fears being eclipsed or humiliated. She clings to her sense of superiority as a shield against her own vulnerabilities.

Lavinia's role in the story is that of a primary antagonist among the students, serving as a constant source of conflict and a mirror to the opposite qualities of generosity, kindness, and humility that Sara embodies. While Miss Minchin represents institutional cruelty and adult hypocrisy, Lavinia represents the petty cruelty of peer rivalry and the tyranny of social hierarchy. She functions as a foil to Sara: where Sara is naturally generous and earns admiration without seeking it, Lavinia is grasping and envious and loses respect the harder she tries to force it. Their conflict is central to many episodes, as Lavinia repeatedly attempts to humiliate Sara, only for Sara's grace and fortitude to expose the emptiness of Lavinia's malice.

Her key relationships extend primarily to Sara, whom she sees as a rival and an enemy, and to Miss Minchin, whom she flatters and manipulates for mutual benefit. She also interacts with the other students in ways that reinforce her status as the school's queen bee: she dismisses Ermengarde as slow and worthless, she bosses around the younger Lottie, and she pressures the other girls to choose sides against Sara. With Becky, the scullery maid, she displays open contempt, treating her as beneath notice except when she can use her to cause trouble. Lavinia's relationship with her own family, particularly her wealthy parents, is one of pride and reliance; she boasts about their connections and uses their money to maintain her wardrobe and position.

In terms of development, Lavinia remains largely unchanged throughout most of the series. She does not undergo a significant moral transformation or come to repent for her actions. Her hatred for Sara persists to the end, though there are moments when her facade falters and her own loneliness or insecurity briefly surfaces. The anime hints at her complexity by showing that her arrogance is partially a response to the pressures of high social standing and the fear of losing her place, but she never fully transcends these limitations. She is not a redeemable character in the traditional sense; instead, she remains a consistent obstacle for Sara, representing the way that pride and envy can harden into permanent cruelty. This lack of a dramatic redemption arc underscores a central theme of the story: that not all people are changed by kindness, and that some remain trapped by their own bitterness.

Her notable abilities are largely social and psychological. She is skilled at reading the emotional climate of the school, manipulating weaker students, and using language as a tool of intimidation. She is also resourceful, as when she reports Ermengarde to Miss Minchin to endanger Sara, showing that she is willing to betray anyone to protect her status. However, her abilities are limited by her inflexibility: she cannot imagine forming genuine friendships, she underestimates the loyalty Sara inspires in others, and she never grasps the truth that true authority comes from character, not from wealth or connections. In the end, she remains a static but effective antagonist, defined by her envy and her unyielding refusal to acknowledge any good in the girl who surpassed her.