The character of Antoinette derives from Charlotte Brontë's poignant and powerful depiction of a deranged Creole outcast in her gothic novel Jane Eyre. Rhys creates a prehistory for Bronte's character, tracing her development from a young solitary girl in Jamaica to a love-depraved lunatic in an English garret. By fleshing out Brontë's one-dimensional madwoman, Rhys enables us to sympathize with the mental and emotional decline of a human being. Antoinette is a far cry from the conventional female heroines of nineteenth- and even twentieth-century novels, who are often more rational and self-restrained (as is Jane Eyre herself). In Antoinette, by contrast, we see the potential dangers of a wild imagination and an acute sensitivity. Her restlessness and instability seem to stem, in some part, from her inability to belong to any particular community. As a white Creole, she straddles the European world of her ancestors and the Caribbean culture into which she is born.

Left mainly to her own devices as a child, Antoinette turns inward, finding there a world that can be both peaceful and terrifying. In the first part of the novel we witness the development of a delicate child—one who finds refuge in the closed, isolated life of the convent. Her arranged marriage distresses her, and she tries to call it off, feeling instinctively that she will be hurt. Indeed, the marriage is a mismatch of culture and custom. She and her English husband, Mr. Rochester, fail to relate to one another; and her past deeds, specifically her childhood relationship with a half-caste brother, sullies her husband's view of her. An exile within her own family, a "white cockroach" to her disdainful servants, and an oddity in the eyes of her own husband, Antoinette cannot find a peaceful place for herself. Going far beyond the pitying stance taken by Bronte, Rhys humanizes "Bertha's" tragic condition, inviting the reader to explore Antoinette's terror and anguish.