She was a princess—the third wife of Prince Stanislaw Albrecht Radziwill. She was a socialite—one of Truman Capote’s ‘Swans.’ And she was an interior designer—mentored by Lorenzo Mongiardino. But Lee Bouvier Radziwill was known to most as the younger sister of Jacqueline Kennedy Onassis. And as the late Princess Margaret would have agreed, that’s not an easy role to play. Radziwill died last February, at the age of 85. Hundreds of objects from her years of collecting—costume jewelry, photography, fine and decorative art, books, and memorabilia—will be offered in a dedicated sale on October 17 at 10 a.m. —L.J.

The collection is on view October 11–15.