Her younger sister, Eugenie, wore a cobalt-coloured creation by British designer Vivienne Westwood.
The top rated designers were Alexander McQueen, Chanel and Vivienne Westwood but all three missed out on a top 10 spot.
From left: Helen Mirren wearing Vivienne Westwood; Sharon Stone in Dior; Hilary Swank in Gucci Premiere; Helena Bonham Carter.