MONTE-CARLO, MONACO - MARCH 18: Princess Camilla of Bourbon-two Sicilies and Prince Charles of Bourbon-two Sicilies 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 Stephane Cardinale - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18:  Princess Camilla of Bourbon-two Sicilies and Prince Charles of Bourbon-two Sicilies 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 Stephane Cardinale - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18: Princess Camilla of Bourbon-two Sicilies and Prince Charles of Bourbon-two Sicilies 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 Stephane Cardinale - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18:  Princess Camilla of Bourbon-two Sicilies and Prince Charles of Bourbon-two Sicilies 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 Stephane Cardinale - Corbis/Corbis via Getty Images)

MONTE-CARLO, MONACO - MARCH 18: Princess Camilla of Bourbon-two Sicilies and Prince Charles of Bourbon-two Sicilies 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: Princess Camilla of Bourbon-two Sicilies and Prince Charles of Bourbon-two Sicilies 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: Princess Camilla of Bourbon-two Sicilies 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 Camilla of Bourbon-two Sicilies 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 Camilla of Bourbon-two Sicilies Sicilies 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 Camilla of Bourbon-two Sicilies Sicilies 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)