Looking perfectly in-sync, the three most-talked about royal ladies joined forces at luxury store, Fortnum & Mason, to unveil a plaque marking the renovation London's Piccadilly district.
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And in a nice touch, Kate had some daffodils pinned to her Missoni coat in honour of St David's Day – an important date in her home on the Welsh island of Anglesey.
Each of the ladies were then presented with posies of the yellow blooms.
The Queen also opted for strategic sartorial style, wearing a duck-egg blue suit inspired by Fortnum & Mason's brand colours.
Inside, the royal party were treated to a tour of the store's extensive food hall.
As a military wife, Kate was particularly interested to meet staff working on the Gifts For Troops scheme, an initiative which sends packages to soldiers serving in Afghanistan.
After making a small piece of royal history with their visit, the monarch and her relatives headed to a tea party for around 150 Fortnum employees, many of whom have worked at the store since her coronation in 1953.
An excited throng of well-wishers greeted the ladies as they left, among them London Mayor Boris Johnson who had arrived by bike.
After her outing in the capital, Prince William's wife will be by the Queen's side again when she and the Duke of Edinburgh head to Leicester on March 8.
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