BERLIN, GERMANY - JULY 19:  German Chancellor Angela Merkel welcomes Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge at chancellery during an official visit to Poland and Germany on July 19, 2017 in Berlin, Germany.  (Photo by Sean Gallup/Getty Images)
BERLIN, GERMANY - JULY 19:  German Chancellor Angela Merkel welcomes Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge at chancellery during an official visit to Poland and Germany on July 19, 2017 in Berlin, Germany.  (Photo by Sean Gallup/Getty Images)
BERLIN, GERMANY - JULY 19: Germany Chancellor Angela Merkel welcomes Catherine, Duchess of Cambridge, and Prince William, Duke of Cambridge, on the balcony of the german Chancellory, on the first day of their visit to Germany on July 19, 2017 in Berlin, Germany. The royal couple are on a three-day trip to Germany that includes visits to Berlin, Hamburg and Heidelberg. (Photo by Michele Tantussi/Getty Images)
BERLIN, GERMANY - JULY 19:  In this handout photo provided by the German Government Press Office (BPA), Chancellor Angela Merkel meets Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, at the beginning of their meeting at the Federal Chancellery during an official visit to Poland and Germany on July 19, 2017 in Berlin, Germany.  (Photo by Guido Bergmann/Bundesregierung via Getty Images)
BERLIN, GERMANY - JULY 19:  In this handout photo provided by the German Government Press Office (BPA), Chancellor Angela Merkel meets Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, at the beginning of their meeting at the Federal Chancellery during an official visit to Poland and Germany on July 19, 2017 in Berlin, Germany.  (Photo by Guido Bergmann/Bundesregierung via Getty Images)