The newlyweds joined the rest of the royal family while riding in horse-drawn carriages to Buckingham Palace, where they all appeared together on the balcony.
Savannah, the daughter of Peter Phillips - the son of Princess Anne and the Queen's oldest grandson, put her hand over George's mouth and then sushed the future king to stop him from talking so much.
Meghan experienced the pomp and pageantry of the event for the first time when she arrived on Horse Guards Parade with Harry in a carriage, along with the Queen's cousin the Duke of Kent.
The younger royals lined up in front of the adults to enjoy the fly-past of modern and historic aircraft, with Prince George and Princess Charlotte standing with their parents, the Duke and Duchess of Cambridge.
The Countess of Wessex, Princess Eugenie, Princess Beatrice and Lady Louise Windsor are also attending the Trooping the Colour ceremony.
The Queen's actual birthday is April 21.
The head of state, who travelled in an Ascot Landau, wore a sky blue coat and dress by Stuart Parvin, and a hat by Angela Kelly. She is the Queen's eldest great grandchild.
Meghan, the new Duchess of Sussex, who has been welcomed into the Royal Family with open arms, has a busy week of appearances ahead. It's only been a few weeks since the Suits star exchanged vows with Prince Harry, but inside sources claim that the actress is having trouble adjusting to her new life in the UK.
He said: "I'm quite proud and I know that a lot of other people are proud of me as well".
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