Crystal Kwok Gam-Yan was born on 13 May 1966 in San Francisco, California, USA. She is an actress and director, known for The Mistress, The Master and Police Story 2. She is married to Richard Wertheimer. They have three children. Crystal Kwok Gam-Yan was born on 13 May 1966 in San Francisco, California, USA. She is an actress and director, known for The Mistress, The Master and Police Story 2. She is married to Richard Wertheimer. They have three children.