TORONTO -- As the Duke and Duchess of Sussex step back from the Royal Family’s frontline duties, could a new pair step forward?

At least one royal expert believes sister princesses Beatrice and Eugenie could fill Harry and Meghan’s vacancy.

Robert Lacey, a royal biographer and historical consultant on Netflix drama The Crown, told HELLO! magazine that it’s actually “quite clear” the pair will step up.

“If two go out, two have got to come in, and those two have got to be Beatrice and Eugenie,” he said.

CTV’s royal commentator Richard Berthelsen isn’t as convinced, calling it an “open question.” The sisters have “never been particularly popular,” he said in an interview with Not to mention, their father, Prince Andrew, recently stepped back from royal duties following scandal surrounding his former association with the now dead convicted sex offender Jeffrey Epstein.

“It’s possible that (Beatrice and Eugenie) may do more within the realm of what they have opted to do, which is some light charity work,” Berthelsen said Monday.

It’s another question whether the sisters could travel around the Commonwealth and undertake official royal duties for the Queen. That is “a little hard to imagine,” he continued.

But the pair stepping up could be the beginning of a solution to what Berthelsen called a “labour shortage” in an aging Royal Family. Some members, including some of the Queen’s cousins who still perform duties, may soon age out of their positions. Princesses Beatrice, 31, and Eugenie, 29, also would address another issue, said Berthelsen:

“There’s kind of a shortage of princesses,” he said. “Most of the members of the Royal Family that are prominent are males. There’s a bit of a gender imbalance.”

Earlier this month, the Queen met with Charles, William and Harry in Sandringham. While the Duke and Duchess of Sussex were acknowledged as the subject of the meeting, Berthelsen said at the time that the scope was probably much wider. The so-called “Sandringham Summit” likely had implications for other junior members of the family, including Beatrice and Eugenie. The talks may have helped define the sisters’ positions further as Harry and Meghan sought a life away from the Crown.

The sisters, who are the daughters of Prince Andrew, have been considered by some experts as a model for how Harry and Meghan could move forward as more junior members of the Royal Family. In fact, Harry has even mentioned his cousins’ lifestyle as a “model,” Lacey pointed out. Beatrice and Eugenie live relatively private lives and are financially independent, but maintain a balance between occasional royal duties and charity work with a few royal patronages.

“They’re not really seen as representing the Queen -- they represent themselves,” said Berthelsen. “They’re kind of in the same world that Prince Harry and the Duchess of Sussex are now.”