"She thinks she is sitting on the French Riviera sipping champagne," read one complaint on Twitter.
Ivanka Trump was attending the event as the guest of Queen Elizabeth along with other members of her family, when she failed to show proper etiquette during the playing of 'The Star-Spangled Banner'.
Known colloquially as the “First Daughter”, Ivanka is understood to be US President Donald Trump’s favourite child.
Donald Trump is set to bring his children and their spouses when he travels to London to visit the Queen next month, according to reports in the US. The American president is said to have told organisers he wants his adult children, Donald Jr, Ivanka, Eric and Tiffany, to meet the Royal Family during the three-day state visit marking the 75th anniversary of D-Day. Prince William and wife Kate, Duchess of Cambridge, are expected to meet the young Trumps and their partners, while Prince Charles and Camilla will reportedly be hosting a tea for Mr Trump and his wife, Melania, at Clarence House.