Menkes was born in Britain. She was educated at Brighton and Hove High School. In the 1960s, she went as a teenager to Paris to study dressmaking. Viewing her first couture show at Nina Ricci sparked her interest in high fashion. On her return from Paris, she read history and English literature at Cambridge University. After Cambridge, she worked for The Times reporting on fashion. In addition to her journalism, she has written several books, particularly on British Royal style. In November, 2009, she appeared as one of the judges on the finale of Lifetime TV series Project Runway.