Lady Gabriella Kingston made a lowkey appearance at the King's birthday celebrations, four months after the tragic passing of her husband Thomas Kingston from suicide.
It's understood that King Charles offered Lady Gabriella a place at the ceremony following the death of Thomas. Lady Gabriella did accept the invitation, but kept away from the cameras and watched the RAF flypast from inside Buckingham Palace.
In a wide-shot, Lady Gabriella could be seen behind the Duke of Kent and Princess Anne's husband, Vice Admiral Sir Timothy Laurence.
The royal was supported by her brother, Lord Frederik Windsor, and his wife, Sophie Winkleman, who is known as Lady Frederik Windsor. Sophie looked gorgeous in photos taken inside Buckingham Palace, wearing a Beulah London dress, while Lord Frederik was dapper in a suit.
Last month would have marked her fifth wedding anniversary with financier Thomas, who was found dead at the age of 45 at his parents' home in the Cotswolds on 25 February.
An inquest at Gloucestershire Coroner's Court on 1 March found that Thomas died from a "catastrophic head injury" and a gun was found near his body. His death was not treated as suspicious, and no one else was involved.
He and Gabriella told the knot on 18 May 2019 at St George's Chapel in Windsor, with the late Queen Elizabeth II, the late Duke of Edinburgh and Prince Harry among the guests.
When Thomas's death was announced by Buckingham Palace in February, Lady Gabriella paid tribute to her late husband in a joint statement with his family, saying: "Tom was an exceptional man who lit up the lives of all who knew him."
The funeral took place on 12 March at the Chapel Royal in St James's Palace with Lady Gabriella, her parents Prince Michael and Princess Michael of Kent and the Prince of Wales in attendance.
The service was followed by a reception in St James's Palace and a private cremation.
Lady Gabriella has reportedly moved back in with her parents at their home at Kensington Palace, having previously shared a home in Notting Hill in west London with her late husband.