The Pierre Berge-Yves Saint Laurent Foundation announced her passing, citing an unspecified "long illness" as the cause of death. WWD's sources report that de la Falaise was diagnosed with cancer last June but wanted to keep her health a private matter. She is survived by her husband, Thadee Klossowski — who she married in 1977 in a Yves Saint Laurent Rive Gauche turban and harem pants — and their daughter, Anna.
De la Falaise met Saint Laurent at 1968, when she was 21, at a tea party given by the designer Fernando Sanchez. She began working for YSL in 1972, designing jewelry and hats for his couture and ready-to-wear collections and producing up to 2,000 pieces of jewelry a year until 2002, when he retired. Later, she collaborated with Oscar de la Renta on his jewelry collections. Her final designs — a line of costume jewelry she created over the Summer — go on sale next month in the shop at the Majorelle Garden in Marrakech.
A few of our favorite Loulou snaps, in the slideshow (NSFW).