HOUNSLOW, ENGLAND - MARCH 17: Catherine, Duchess of Cambridge and Prince William, Duke Of Cambridge attend the annual Irish Guards St Patrick's Day Parade at Cavalry Barracks on March 17, 2018 in Hounslow, England. (Photo by Chris Jackson/Getty Images)
HOUNSLOW, ENGLAND - MARCH 17: Catherine, Duchess of Cambridge and Prince William, Duke Of Cambridge attend the annual Irish Guards St Patrick's Day Parade at Cavalry Barracks on March 17, 2018 in Hounslow, England. (Photo by Chris Jackson/Getty Images)
