Clarence House shared a photo on its social media accounts of Meghan at the Queen's Service of Thanksgiving alongside a caption which read: "Happy birthday to The Duchess of Sussex! [balloon emoji]."
WATCH: Prince Harry discusses his and Meghan Markle's visit with the Queen
Meghan will no doubt have a fun-filled day with her husband Prince Harry and their two children, three-year-old Archie and Lilibet who turned one in June. The family of four marked Lilibet's first birthday in the UK amid the Queen's Platinum Jubilee celebrations.
It was recently reported that Prince Charles met his granddaughter Lili and reunited with his grandson Archie during their latest visit. According to a senior royal source, the meeting was "very emotional", with Prince Charles and Camilla delighted to spend time with Harry and Meghan and their two children.
The picture Clarence House shared of Meghan
The couple travelled to London from their California home just before Lili's first birthday, enjoying some of the Queen's Platinum Jubilee celebrations as well as spending private time with their family.
Speaking at the briefing of Clarence House's annual review, the source said of the pair: "It was fantastic to see them. It was wonderful to have them back in Britain. The Prince and the Duchess were absolutely thrilled to see them.
Meghan has turned 41
"The Prince, of course, hasn't seen his grandson Archie for a bit of time and so it was very, very, very special to have some time with him. He hadn't met Lili, his granddaughter, and so to meet her was very emotional, a very, very wonderful thing."
Lili also met her namesake, her great-grandmother the Queen, for the first time and enjoyed her first birthday party at Frogmore Cottage, Meghan and Harry's UK base.
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