CANBERRA, AUSTRALIA - APRIL 20:  Catherine, Duchess of Cambridge, Prince William, Duke of Cambridge and their son Prince George of Cambridge arrive at Fairbairn Airport on April 20, 2014 in Canberra, Australia. The Duke and Duchess of Cambridge are on a three-week tour of Australia and New Zealand, the first official trip overseas with their son, Prince George of Cambridge.  (Photo by Cole Bennetts/Getty Images)