and are said to be "waiting in the wings" for to make a major move when he becomes King, according to a royal expert. The Prince of Wales is thought to will look like under his reign.

King Charles's "slimmed-down" monarchy has relied heavily on the King's siblings, Princess Anne and Prince Edward, as well as his son, Prince William, to juggle the most of the royal workload. But it has also been supported by non-working members of the Firm, namely the King's nieces, Princess Beatrice, Princess Eugenie.

The York sisters have been quietly supporting the crown throughout various endeavours and roles.

Now a royal expert has suggested that they could play a key role in William's monarchy when he becomes King.

Royal author Ingrid Stewart told New Day magazine: "They [Beatrice and Eugenie] are valuable assets and I'm certain they'll get involved with royal duties when William becomes King.

"I'm sure they would like to do more and they're waiting in the wings to be asked."

The Daily Mail's Richard Eden shared a similar opinion and claimed the York sister could have something to "give" during William's reign.

He told the Palace Confidential podcast: "Prince William, like his father, has always favoured slim-down monarchy as the future and what that looks like now is just William and Catherine and their children."

He added: "From what I'm hearing is that Prince William is starting to see the value of his cousins and what, in the long term, they could give. Obviously, we had Queen Elizabeth, who was supported throughout her reign by her cousins, such as the Duke of Kent, the Duke of Gloucester, and the ones I'm writing about this week are Princess Beatrice and Eugenie.

"They're doing more and more. They're private duties really, in terms of charity work, but I think Prince William and his father are noticing this and appreciating it."