Catherine, Princess of Wales, is one of the most popular members of the British royal family. In fact, according to one poll taken earlier this month, even as conspiracy theories about her health were swirling, she is the most popular member.

She is the glamorous commoner who married a prince and has a beautiful family. She created a role for herself championing early childhood development. She seems relatable and has often been the picture of health and fitness.

It is also clear that after her shock cancer diagnosis, she will be taking a break from public-facing duties for some time — even as her father-in-law, King Charles III, is enmeshed in his own struggle with cancer. Over the weekend, Kensington Palace released a statement saying that Catherine and Prince William were “enormously touched by the kind messages” and also “grateful” that the public understood their request for privacy.

The double cancer blow raises questions about an institution under strain with fewer figures to make public appearances. Less than a year after Charles’s coronation, two of the most senior members of the royal family are facing serious health concerns — and the nation is still affected by the death of long-ruling Queen Elizabeth II.

“It’s not their fault, but there’s not enough of them to go around,” said Hugo Vickers, a royal biographer. He added that Catherine was “crucial to the royal family. … Who would you stand out in the street to see go by? Catherine.”

The country, meanwhile, was only just starting to get used to the absence of Elizabeth and the end of her 70 years on the throne. The reign of Elizabeth was “like a ship that sailed pretty smoothly, with occasional choppy waters, but you always had a sense of a royal family on the throne” said Craig Prescott, a royal historian at Royal Holloway, University of London. It now seems as if “the ship itself is in a bit of difficulty.”

Charles is, of course, the most important member of the royal family. He is still carrying out his constitutional duties behind the scenes, and the public has caught glimpses of him in recent weeks. But it’s William and Catherine, the main connection the monarchy has with younger generations, who reign in the popularity polls.

Perhaps one of the reasons the institution seems more unsettled is that the palace has been more transparent about health issues — though still falling short of modern standards, according to many royal observers.

In the early 1950s, King George VI’s lung cancer was kept out of the public domain. Neither his heirs nor his subjects knew how serious things were and his death came as something of a shock. When Elizabeth had health problems, they were generally relayed, if at all, in vague terms — the palace might say she was experiencing “some discomfort” or “mobility issues.”

Buckingham Palace and Kensington Palace have not revealed what kind of cancer Charles and Catherine have, nor what the prognosis is. But the diagnoses raise questions about who will step up while they receive treatment.

“We’re left with a very small gang, and therein lies a problem,” said Joe Little, managing editor of Majesty Magazine. “I’m sure behind the scenes a massive review of working royal life is being undertaken because there are less people around.”

Before he took the helm, Charles reportedly said that he wanted a “slimmed-down” monarchy — perhaps not quite as slim and informal as some of the “bicycling monarchies” of Scandinavia — with a smaller core of working royals.

Expectations that he might reduce the number of senior royals involved have yet to be met, but the numbers of working royals was already falling in recent years.

Elizabeth and her husband, Prince Philip, have died. Prince Harry and Meghan, Duchess of Sussex, decamped to California. Prince Andrew was cast into the royal wilderness after he settled a lawsuit with Virginia Giuffre, an American who said she was forced to have sexual encounters with him when she was a teenager.

In recent weeks, Queen Camilla, ironically once seen as a threat to the monarchy, has been a royal stalwart, attending several events on her own, giving speeches and handing out accolades. William is also expected to pick up some of the slack, but his father and wife have cancer and he has three young children.

The seemingly indefatigable Princess Anne — the king’s younger sister — soldiers on. The other working members of the family are: Prince Edward and Sophie, the Duke and Duchess of Edinburgh; Prince Richard and his wife Birgitte, the Duke and Duchess of Gloucester; Prince Edward, the Duke of Kent, and his younger sister, Princess Alexandra. The youngest person in this group is 59.

Working royals are patrons to thousands of charities — having a royal’s name attached to a charity adds kudos and helps draw attention to causes. But hundreds of “patronages” have remained vacant after the deaths of Elizabeth and Philip and the departures of Andrew, Harry and Meghan.

Royal commentators have speculated about the prospect of bringing Prince Andrew’s two daughters, Princess Beatrice, 35, and Princess Eugenie, 34, on board as working royals.

But Little, editor of Majesty magazine, said he thought that if Charles was going to do that he would have done so by now, “but you know, extenuating circumstances and all.” He thought it would be more likely that the royals cut back on their engagements for now.

While officials haven’t given many details about the health status of Catherine or Charles, the messaging has been upbeat. Prime Minister Rishi Sunak let slip that Charles’s cancer was “caught early,” although this was not confirmed by Buckingham Palace. Catherine said that she was receiving “preventive chemotherapy” and said that “I am well and getting stronger every day.”

Paddy Harverson, a former spokesman for William and Catherine, denied that the institution was “fragile.”

Speaking to the BBC on Sunday, he said that going forward, “the nation just needs to adjust, and the media and everyone who follows this, to a smaller family but still very busy doing what they do in their own way.”