The royal, who joins the Firm regularly at various family events, appeared to pay a poignant tribute to her late mother by wearing a very sentimental piece of jewellery. Lady Sarah donned her mother’s diamond and sapphire brooch, which was pinned on the left lapel of her navy blue coat.

Margaret wore the brooch plenty of times throughout her life and her daughter inherited it upon her death in 2002.

Little is known about the family heirloom, but it is believed to have been owned first by Queen Mary, who gave it as a wedding gift to Margaret and Queen Elizabeth’s mother, the Queen Mother, who then gave it to her younger daughter.

Lady Sarah is married to Daniel Chatto and they share two sons, Samuel and Daniel.

The Chattos do not undertake royal duties but have frequently attended several high-profile events alongside the rest of the royals, including the King's Coronation, the Princess of Wales's Christmas Carol concerts and Royal Ascot.

Prince William and Princess Catherine’s daughter looked adorable in a beige coat with brown trim as she walked alongside her parents and siblings, Prince George and Prince Louis.

Royal fans were quick to point out Charlotte’s resemblance to her royal relative.

One user said on X: “The resemblance of Princess Charlotte with Lady Sarah Chatto is unbelievable. Windsor genes are so strong in Charlotte she definitely inherited them. They practically look the same.”

Another one agreed: “I’ve always said she resembles Lady Sarah.” A third one said: “OMG! You would swear she is Sarah Chatto’s daughter, but she is not.”