Lavinia is Ezra's wooden, stiff-shouldered, flat-chested, thin, and angular daughter. She is garbed in the black of mourning. Her militaristic bearing, a mark of her identification with her father, symbolizes her role as a functionary of the Mannon clan or, to use Christine's terms, as their sentry. Lavinia appears as the keeper of the family crypt and all its secrets, figuring as an agent of repression throughout the play. She will urge Orin in particular to forget the dead, compulsively insist upon the justice of their crimes, and keep the history of the family's past from coming to light. Lavinia's repressive stiffness and mask-like countenance mirrors that of the house, the monument of repression erected by her ancestors to conceal their disgraces. Ultimately this manor becomes her tomb, Lavinia condemning herself to live with the Mannon dead until she and all their secrets with her die.

Despite her loyalties to the Mannon line, Lavinia appears as her mother double from the outset of the play, sharing the same lustrous copper hair, violet eyes, and mask-like face. Christine is her rival. Lavinia considers herself robbed of all love at her mother's hands, Christine not only taking her father but her would-be lover as well. Thus she schemes to take Christine's place and become the wife of her father and mother of her brother. She does so upon her mother's death, reincarnating her in her own flesh.

In doing so, Lavinia comes to femininity and sexuality. Lavinia traces a classical Oedipal trajectory, in which the daughter, horrified by her castration, yearns to become the mother and bear a child by her father that would redeem her lack. Orin figures as this child as well as the husband she would leave to be with her son, that is, Peter substituting as Brant.