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Lucy responds with rage and a wish to cut the flowers down, because to her they stand for an imposed culture that taught her to love things from someone else's landscape. Mariah's innocent gift and Lucy's fury show how the same object can mean delight to the colonizer's heir and humiliation to the colonized.
Mariah is kind, generous, and sincerely wants Lucy to share her pleasures and even claims Native American ancestry to signal kinship with the dispossessed. Lucy sees that this goodwill depends on a comfort that lets Mariah treat history as a shared feeling rather than a structure she benefits from. Looked at this way, warmth from the powerful can be a way of not seeing the gap, and it can make resentment from the less powerful look like ingratitude.
Lucy leaves her mother's letters unopened because she knows that reading them would pull her back into the identity her mother shaped, one that ranked Lucy below her brothers in ambition. The novella presents breaking from the mother and breaking from the colonial island as the same act. Both require a deliberate coldness, even cruelty, because a milder separation would be absorbed back into the old dependency.
From her place in the household, Lucy notices early that Lewis is having an affair with Dinah, Mariah's best friend, while Mariah stays unaware until the marriage collapses. Because she is a domestic employee, Lucy is present for everything and counted as nothing, so she sees what the family cannot admit about itself. The episode shows the worker as the one reliable witness to the employer's private life, and it shows Mariah's idealized family as a performance.