The Queen was joined by several members of King Charles' relatives at a star-studded outing on Wednesday night.
Camilla, 76, enjoyed performances by Dame Judi Dench, Gary Oldman and Robert Lindsay as she attended an event celebrating the work of William Shakespeare.
As well as being supported by the Duke and Duchess of Gloucester, who are full-time working royals, the Queen was also joined by Lord and Lady Frederick, and Lady Gabriella Windsor and her husband, Thomas Kingston.
Lady Frederick, also known as Sophie Winkleman, looked elegant in a navy button-up tea dress, while her husband, Lord Frederick, wore a matching blue tie.
They were coordinated with Lord Frederick's sister, Lady Gabriella, who donned a cobalt blue pussy-bow blouse and a navy satin skirt. Her financier husband, Thomas, also sported a bright blue scarf.
Camilla, who wore a green velvet dress from ME+EM dress, met actors, authors, directors, and representatives of the National Theatre and the Royal Shakespeare Company at the celebration, joining guests for a group photograph.
The King and Queen hosted a reception at Windsor Castle in July 2023 to celebrate the work of Shakespeare in the 400th year of the first folio. Shakespeare’s first folio, published in 1623, contains 36 of his plays.
The Queen made a solo appearance at the event as the King returned to Sandringham following a 24 hour stay in London. It is believed he flew to the capital from Norfolk for cancer treatment.
Camilla was inundated with gifts at her engagement, including a large bouquet of flowers. She was also given two matching jumpers with a heart on them by event host Gyles Brandreth, who said he hoped they would keep the King and Queen "warm on those cold winter nights".
It is understood the reception was due to be a joint event for the King and his wife, but since his cancer diagnosis Charles has postponed all public-facing duties, however he is continuing with behind-the-scenes work on his red boxes of state papers.
Many of the guests signed a card and left messages of well-wishes to Charles.