The Royal Family tweeted: “Congratulations to The Duke and Duchess of Sussex on the birth of Lilibet Diana!
“The Queen, The Prince of Wales and The Duchess of Cornwall and The Duke and Duchess of Cambridge are delighted with the news.
“Lilibet is Her Majesty’s 11th great-grandchild.”
However, royal expert Daniela Elser has claimed the Queen was “blindsided” by Harry and Meghan amid an ongoing feud between the Firm and the Duke and Duchess of Sussex.
Ms Elser told the NZ Herald: “Lending further weight to the possibility that the Queen et al were blindsided by Harry and Meghan’s reveal was that even after news of Lili’s birth had already broken and was being carried by TV stations, Her Majesty’s official Twitter account was still posting about a recent engagement carried out by Princess Anne.
“After all, leaving the other side looking red-faced has never been known to help tamp down inflamed tempers and or improve highly-strung intra-family politics.”
The Royal Family took at least 94 minutes to congratulate the Duke and Duchess of Sussex on their daughter.
At his funeral, the Queen reportedly left a handwritten note on his coffin and signed it “Lilibet”.
The new baby is the Queen’s 11th great-grandchild, and the first to be born since Philip’s death.
It is not known if or when the Queen will get to meet her latest great-grandchild.
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The Queen is “upset” at being dragged into a further rift between Prince Harry and the Royal Family on what would have been Prince Philip’s 100th birthday today.
A Palace insider insisted Her Majesty was “never asked” by the Duke and Duchess of Sussex if they could use her childhood nickname Lilibet for their newborn daughter.
But a war of words erupted as their lawyers threatened to sue the BBC and other news bodies for saying that – challenging the Palace’s view of events.
That then pitched Harry against his 95-year-old grandmother, to all intents and purposes.
Tensions building behind the scenes flared up into a full-scale public row, after the broadcaster reported a Palace source as saying that the Prince and his American wife had not asked the Queen about the names they wanted for their daughter.
Meghan, 39, had given birth to Lilibet “Lili” Diana Mountbatten-Windsor at a hospital in Santa Barbara, California last Friday.
Prince William was reportedly furious with his father Prince Charles after he shared some personal details about his eldest grandson Prince George – which could explain why the Prince of Wales only subtly mentioned the newest addition to his family, Lilibet, in public this week.
William is renowned for being very protective over his three children, and regularly draws a line between his public life and what he is willing to share with the media.
Charles, however, has been more forthcoming with details about his grandchildren in the past — to his eldest son’s displeasure.
As the Firm celebrated Harry becoming a father for the second time — following the arrival of Lilibet Diana last Friday — royal watchers were waiting to see how the Prince of Wales addressed the latest addition to his family.
On his shared social media accounts with the Duchess of Cornwall, Charles wrote: “Congratulations to Harry, Meghan and Archie on the arrival of baby Lilibet Diana. Wishing them all well at this time.”