MONTE-CARLO, MONACO - MARCH 18: (L-R) Beatrice Borromeo,Pierre Casiraghi, Princess Caroline of Hanover, Karl Lagerfeld and Charlotte Casiraghi attend the Rose Ball 2017 To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco. (Photo by Pascal Le Segretain/Getty Images)

MONTE-CARLO, MONACO - MARCH 18: (L-R) Beatrice Borromeo,Pierre Casiraghi, Princess Caroline of Hanover, Karl Lagerfeld and Charlotte Casiraghi attend the Rose Ball 2017 To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco.  (Photo by Pascal Le Segretain/Getty Images)

A hostess (R) hamds flowers to Caroline of Monaco, Princess of Hanover (L) as she arrives for the annual Rose Ball at the Monte-Carlo Sporting Club in Monaco on March 18, 2017. The Rose Ball is one of the major charity events in Monaco. Created in 1954, it benefits the Princess Grace Foundation. / AFP PHOTO / VALERY HACHE (Photo credit should read VALERY HACHE/AFP/Getty Images)

A hostess (R) hamds flowers to Caroline of Monaco, Princess of Hanover (L) as she arrives for the annual Rose Ball at the Monte-Carlo Sporting Club in Monaco on March 18, 2017. 
The Rose Ball is one of the major charity events in Monaco. Created in 1954, it benefits the Princess Grace Foundation.  / AFP PHOTO / VALERY HACHE        (Photo credit should read VALERY HACHE/AFP/Getty Images)

Caroline of Monaco, Princess of Hanover (L) and German fashion designer Karl Lagerfeld arrive for the annual Rose Ball at the Monte-Carlo Sporting Club in Monaco on March 18, 2017. The Rose Ball is one of the major charity events in Monaco. Created in 1954, it benefits the Princess Grace Foundation. / AFP PHOTO / VALERY HACHE (Photo credit should read VALERY HACHE/AFP/Getty Images)

Caroline of Monaco, Princess of Hanover (L) and German fashion designer Karl Lagerfeld arrive for the annual Rose Ball at the Monte-Carlo Sporting Club in Monaco on March 18, 2017.
The Rose Ball is one of the major charity events in Monaco. Created in 1954, it benefits the Princess Grace Foundation.  / AFP PHOTO / VALERY HACHE        (Photo credit should read VALERY HACHE/AFP/Getty Images)

MONTE-CARLO, MONACO - MARCH 18: Princess Caroline of Hanover attends the Rose Ball 2017 To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco. (Photo by Pascal Le Segretain/Getty Images)

MONTE-CARLO, MONACO - MARCH 18: Princess Caroline of Hanover attends the Rose Ball 2017 To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco.  (Photo by Pascal Le Segretain/Getty Images)

MONTE-CARLO, MONACO - MARCH 18: Princess Caroline of Hanover attends the Rose Ball 2017 To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco. (Photo by Stephane Cardinale - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18:  Princess Caroline of Hanover attends the Rose Ball 2017 To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco.  (Photo by Stephane Cardinale - Corbis/Corbis via Getty Images)