LONDON, ENGLAND - FEBRUARY 11: Catherine, Duchess of Cambridge attends The Portrait Gala 2014: Collecting To Inspire at the National Portrait Gallery on February 11, 2014 in London, England. (Photo by Karwai Tang/WireImage)
LONDON, ENGLAND - FEBRUARY 11: Catherine, Duchess of Cambridge attends The Portrait Gala 2014: Collecting To Inspire at the National Portrait Gallery on February 11, 2014 in London, England. (Photo by Karwai Tang/WireImage)
LONDON, UNITED KINGDOM - FEBRUARY 11: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Catherine, Duchess of Cambridge (wearing Queen Elizabeth II's Cartier 'Nizam of Hyderabad' diamond necklace, a wedding present gifted to her in 1947 by Mir Osman Ali Khan, 7th Nizam of Hyderabad) attends The Portrait Gala 2014: Collecting to Inspire at the National Portrait Gallery on February 11, 2014 in London, England. (Photo by Max Mumby/Indigo/Getty Images)
LONDON, UNITED KINGDOM - FEBRUARY 11: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Catherine, Duchess of Cambridge wears the Nizam of Hyderabad diamond necklace as she attends The Portrait Gala 2014: Collecting to Inspire at the National Portrait Gallery on February 11, 2014 in London, England. (Photo by Max Mumby/Indigo/Getty Images)
