The celebration – which honors the Queen’s 70 years on the throne – kicked off on Thursday with the Trooping the Colour ceremony.
Middleton stunned during the ceremony in a white Alexander McQueen coat dress, paired with her late mother-in-law’s diamond and sapphire earrings. She also wore Diana’s matching necklace.
Diana wore the accessories to the 1996 Met Gala where she wore a navy slip dress.
People have also drawn comparisons to Middleton’s entire look being inspired by another Diana moment in 1991. At the time, the late-princess wore an all-white look to watch a parade of military personnel who served in the Gulf War.
Middleton, whose engagement ring once belonged to Diana, has been known to honor Diana in past fashion looks. In 2018, the Duchess attended a state banquet at Buckingham Palace and wore the Lover’s Knot tiara.
This tiara was a favorite of Diana’s and was worn by the Queen several times as well.
The Duchess of Cambridge was not the only member of the royal family honoring the past during the Platinum Jubilee celebrations. Middleton dressed her son, Prince Louis, 4, in the same sailor suit Prince William wore during the Trooping of Colour ceremony when he was just 2-years-old.
Queen Elizabeth’s Platinum Jubilee has brought the royal family together, including Prince Harry and Meghan Markle.
They were not present during the Trooping of Colour ceremony since they aren’t senior members of the royal family. The couple is expected to attend Friday’s jubilee celebration.
Queen Elizabeth announced on Thursday that she will not be attending the Service of Thanksgiving event held on Friday.
“Taking into account the journey and activity required to participate in tomorrow’s National Service of Thanksgiving at St Paul’s Cathedral, Her Majesty with great reluctance has concluded that she will not attend,” the palace said in a statement.