Zara Tindall was every inch a royal in a spellbinding baby blue coat dress designed by Laura Green at King Charles' coronation on Saturday.
The wife of Mike Tindall looked effortlessly regal in the luxurious tailored piece, which she teamed with coordinating shoes and her East/West clutch bag from Strathberry in Forget-Me-Knot blue.
Most poignant, however, was Zara's glittering diamond brooch pinned to the lapel of her Cinderella-blue ensemble. The sparkling accessory, which resembles a rosette motif with delicate drop tassels, was actually Princess Anne's festoon brooch - a gift lovingly given to her by King Charles for her wedding day in 1973.
The Princess Royal has the entire suite of festoon diamonds in her personal collection, including a tiara, earrings, necklace and brooch.
The earrings and necklace were believed to have been given to the royal on her 18th birthday by her parents, the late Queen Elizabeth II and former Duke of Edinburgh, while the festoon tiara was given to the Princess by a Hong Kong-based WorldWide Shipping Group after she christened one of their ships.
King Charles completed his sister's diamond collection just four years later, gifting her the festoon diamond brooch in honour of her nuptials to Captain Mark Phillips.
The now 72-year-old royal recently combined the entire married collection for a banquet at the Guildhall during the Spanish state visit in 2017.
It is not uncommon for the royals to share their heirlooms, or indeed, their clothes. The Duchess of Edinburgh often lends her glittering dresses and tailored occasionwear to her 19-year-old daughter Lady Louise Windsor, and the Princess of Wales regularly twins with her daughter Princess Charlotte in coordinated clothes.
On Saturday, Princess Charlotte made her designer debut at the coronation in a breathtaking ivory dress designed by Sarah Burton for Alexander McQueen.
The whimsical gown, embroidered with botanical motifs representing the four nations of the UK, was a bespoke version of her mother's coronation dress - proving there is no occasion to grand to match with your mini style twin.