The royal family have been supporting the Queen since the death of her husband, the Duke of Edinburgh, at the age of 99 on 9 April.
The Duchess of Cornwall was the latest visitor to Windsor Castle on Thursday after she and Prince Charles made an emotional visit to Marlborough House in central London, where they saw some of the flowers which had been left in memory of Prince Philip.
Camilla, 73, was spotted in the passenger seat, wearing a face mask as she was driven from the Queen's Berkshire residence, where she and Prince Philip had been isolating for much of the past year amid the pandemic.
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Earlier in the week, the monarch's cousin, Prince Richard, the Duke of Gloucester, and his wife Birgitte, the Duchess of Gloucester, were also pictured driving to Windsor Castle.
The couple were both dressed in black attire, with the Duke in the passenger seat.
The Duke and Duchess of Gloucester pictured driving to Windsor Castle
The guest list for the Duke's funeral at St George's Chapel in Windsor was confirmed by Buckingham Palace on Thursday, and the Duke of Gloucester is among the royals who will attend. The COVID-19 restrictions means that only 30 guests will be able to attend the service.
The Queen's cousin Prince Michael of Kent is not on the guest list, nor is his wife Princess Michael of Kent, or the Duchess of Kent and the Duchess of Gloucester.
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Charles and Camilla viewed floral tributes for Prince Philip at Marlborough House
Prince Richard cut short his career as an architect to devote his life to royal duties following the death of his older brother Prince William in 1972.
Mostly operating behind the scenes away from the glare of the media, the Gloucesters, with the Kents and Princess Alexandra, are part of the band of minor royals formed of the monarch's cousins, who have supported the monarch and Philip during her reign.
Prince Richard married Danish-born Birgitte Eva van Deurs Henriksen in July 1972. The couple have three children, Alexander Windsor, Earl of Ulster, Lady Davina Windsor and Lady Rose Gilman.
The Prince of Wales, and the Earl and Countess of Wessex visited Her Majesty shortly after Prince Philip's passing. A tearful Sophie spoke to reporters as she departed the grounds and said: "The Queen has been amazing."
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