What does the "pearl pin" that Franklin gives to Eleanor represent in the novel, White Houses?

The pearl fleur-de-lis pin that Eleanor gives Hick at the end of the chapter titled "Heart of My Heart" (79) is a symbol of the peculiar symbiotic relationship between Hick, Eleanor, and Franklin. The pin was originally a gift from Franklin to Eleanor. Hick refers to it as "Another heirloom, from him to her to me" (89). Eleanor assumes that her husband would not have minded her giving the pin to Hick just as he did not mind the fact that the two women were having an extramarital affair.