LUXEMBOURG, LUXEMBOURG - MAY 11:  Catherine, Duchess of Cambridge (3rd R) calls on Their Royal Highnesses Grand Duke Henri of Luxembourg (3rd L), Grand Duchess Maria Teresa of Luxembourg (2nd R),  Princess Alexandra of Luxembourg (L), Princess Stephanie of Luxembourg (2nd L) and Prince Guillaume of Luxembourg (R) during a one day visit to Luxembourg at Palais Grand Ducale on May 11, 2017 in Luxembourg, Luxembourg.  (Photo by Jeff Spicer/Getty Images)