Because it consists of a series of letters between close friends, The Coquette's mood is intimate throughout. Initially lighthearted and witty, the mood gradually grows grim and tragic as Eliza spirals downward and ultimately dies.
The first chapters of the novel are lighthearted and fun, focusing on the manners and conventions of Eliza's society and reflecting her own desire to enjoy herself after the death of her unwanted fiancé, Mr. Haly. Even when Eliza argues with other characters, like Mrs. Richman, about the propriety of her own behavior, she never becomes upset for long, and the stakes of such interactions for her reputation and marital prospects seem low. However, as Eliza's attraction to Sanford becomes more powerful, and his own coldhearted manipulation of her feelings more evident, the novel takes on a much grimmer mood. This intensifies as Eliza grows more careless about her reputation and her chances of making a respectable marriage dwindle. As Julia describes Eliza's worsening mental state in letters to Lucy, as well as her suspicions that Eliza is secretly meeting with Sanford, Eliza's social ruin and death begin to seem unstoppable.
When Eliza runs away from home to give birth at an obscure inn, the novel ends on a lurid and tragic note. Even though the characters are reluctant to mention Eliza's sexual transgressions or even the baby to whom she gives birth, they dwell on the sad details of her death, describing the "forlorn wanderer" departing home to give birth among strangers and imparting details designed to evoke pity in the reader, like the genteel manners Eliza exhibited even in her final moments. Mrs. Wharton's speeches and the mournful inscription on Eliza's gravestone contribute to the novel's ending on a note of overwhelming sadness.
