Who is Charity in the novel, Alternate Side?

Charity is the Nolans' Jamaican-American housekeeper. When Oliver and Rachel were children, she was their nanny, and has since stayed on to help out around the house for Nora and Charlie. Charity is extremely devoted to the twins; it is noted, for example, that "You couldn't mention the word Harvard around Charity because Rachel had been denied admission, and Nora suspected that she had found and destroyed all photographs of the girl who had broken up with Oliver senior year of high school" (67). Charity is also friendly with the domestic staff of the other houses in the neighborhood, so she occasionally shares information with Nora about the Fisks and the other families.