About a week after Tilly and Delphine move in, Mrs. Hanrahan comes to see how they're settling in.
She realizes what no one else has: Delphine is one of the gens de couleur, or free people of color, of New Orleans.
To say Mrs. Hanrahan is racist is a bit of an understatement. However, she's not quite racist enough to take Delphine up on her offer to leave; she still wants Delphine's rent money.
We pause to bring you a historical note on color and race in the 19th century. It's not all black and white, to say the least. See, Mrs. Hanrahan has probably dealt with her share of racism against the Irish, who immigrated to the United States in large numbers due to the Irish Potato Famine. In the North, Irish immigrants often competed with free people of color for a limited number of jobs, which led to resentment and negative feelings between these groups. You'd think discrimination would lead oppressed groups to work together, but as Tilly puts it, "people aren't made that way" (6.59).
After Mrs. Hanrahan leaves, Tilly asks Delphine to tell her and Dr. Hutchings her real story.
Delphine explains that she is a femme de couleur libre, or a free woman of color. She and the other women in her family are part of a system called plaçage.
Since her grandmother's day, each generation has groomed its girls to have a relationship—but not a marriage—with a wealthy white man who provides for them. These men usually have two families, a traditional white family and a family of color.
Delphine's mother knows that the coming war will destroy the delicate racial balance that makes this system possible, so she sent Delphine north to safety, where she will be able to pass as a white woman, or at the very least maintain her freedom.