Charlotte Casiraghi (C) 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)

Charlotte Casiraghi (C) 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)

Charlotte Casiraghi poses a 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)

Charlotte Casiraghi poses a 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)

Charlotte Casiraghi 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)

Charlotte Casiraghi 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)

MONTE-CARLO, MONACO - MARCH 18: (EDITORS NOTE: NO TABLOIDS) - Charlotte Casiraghi, Juliette Maillot and Mona Walravens during the Rose Ball 2017 Secession Viennoise To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco. (Photo by Pierre Villard/Palais Princier/ SBM/SC Pool - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18:  (EDITORS NOTE: NO TABLOIDS)  - Charlotte  Casiraghi, Juliette Maillot and Mona Walravens during the Rose Ball 2017 Secession Viennoise To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco.  (Photo by Pierre Villard/Palais Princier/ SBM/SC Pool - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18: (EDITORS NOTE: NO TABLOIDS) Charlotte Casiraghi attends the Rose Ball 2017 Secession Viennoise To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco. (Photo by Pierre Villard/ Palais Princier/ SBM/ SC Pool - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18:  (EDITORS NOTE: NO TABLOIDS)  Charlotte Casiraghi attends the Rose Ball 2017 Secession Viennoise To Benefit The Princess Grace Foundation at Sporting Monte-Carlo on March 18, 2017 in Monte-Carlo, Monaco. (Photo by Pierre Villard/ Palais Princier/ SBM/ SC Pool - Corbis/Corbis via Getty Images)