In a tweet shared on Monday morning, officially breaking the royal family's silence since the fallout surrounding Prince Harry's memoir, the account shared: "Wishing The Princess of Wales a very Happy Birthday today!"
The tweet was accompanied with a picture of Kate accepting flowers from an adorable little girl.
The mum-of-three will likely celebrate her 41st birthday in private.
Royal supporters also sent birthday tweets to Kate, with one person writing: "Wishing a very happy birthday to Catherine the Princess of Wales."
Another fan wrote: "Sending Happy Birthday wishes from America to the Princess of Wales and her family, and thoughts and prayers for a happy and blessed day today and many more in the future."
A third penned: "Happy Birthday to the Princess of Wales, the beautiful Kate Middleton, future Queen of Great Britain!"
Kate's birthday this year come during a period of turmoil within the royal family as Prince Harry revealed details about his relatives - including his sister-in-law - in leaked extracts from his memoir Spare, which is due for release on Tuesday.
On Sunday (8 January), the Duke of Sussex was interviewed about the shocking revelations in his book in a 90-minute interview with ITV journalist Tom Bradby.
The explosive memoir includes allegations that Harry was physically attacked by his brother Prince William, and details disagreements between his wife, Meghan Markle, and Kate.
In Harry’s account of the disagreement between Meghan and Kate, the latter had forgotten a detail prior to Harry and Meghan’s wedding in 2018. This prompted Meghan to comment that Kate must have ‘baby brain,’ according to Harry’s account.
Kate had given birth to her and Prince William’s third child, Prince Louis, in April 2018, a mere few weeks before Harry and Meghan’s nuptials.
Harry explained the events after the ‘baby brain’ comment, alleging that his sister-in-law didn’t appreciate the remark.
And in June, the month after the Duke and Duchess of Sussex’s wedding, Harry recalled that both couples met for a reconciliatory tea at Kensington Palace to discuss the topic.
“You talked about my hormones,” Kate allegedly said. “We are not close enough for you to talk about my hormones!”
The remark had such an effect on Kate it left her gripping the upholstered side of her chair so intensely that her fingers went white, according to Harry’s book.
The Invictus Games founder said Meghan was left confused by the reaction as she would say something similar to her own friends.
Buckingham Palace has not responded to Harry's allegations. Tyla has reached out for comment.
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