'Suffering in Silence': Kate Middleton's 'Responsibility to Work' Is Weighing Heavily on Future Queen as She Feels 'Guilt' Over Long Recovery

Kate, Princess of Wales, underwent a "serious" abdominal procedure on January 16, which was followed by the discovery of cancer in the region the following month. While many would easily forgive the future queen's need to heal, recover, and cope with chemotherapy treatments, HRH is said to be feeling "guilt" over her predicament.

"William, and her respon­sibility to her work, are weighing heavily on Kate," a royal insider spilled.

Although King Charles III has returned to work after being diagnosed with cancer in February, Kate is still taking her time to recuperate from her battle with the disease. Prince William also returned to royal duties in late April after spending weeks at his wife's side as she received preventative treatments.

"Kate has guilt that Charles, who’s also battling cancer, is out there doing his part," the source added.

This follows counter reports that suggested the princess was "in good spirits" when she and William celebrated their 13th wedding anniversary on April 29.

"She remains a ray of light in what can often be a suffocatingly stuffy environment behind palace walls," royal author Christopher Andersen told an outlet at the time.

"When they celebrated their 12th anniversary by releasing a photo of themselves smiling broadly on bicycles, no one could have imagined that a year later both Kate and the king would be battling cancer," he added. "More than ever, William and Kate have reason to include the children in everything and keep the prevailing mood as upbeat as possible. Despite her challenges, Kate is incapable of being anything but resolutely cheerful around George, Charlotte, and Louis."

Although it is not known exactly how the monarch and queen consort-in-waiting celebrated their special day, numerous analysts and royal insiders were hard at work beforehand trying to predict the duo's plans.

"We've got the anniversary of William and Catherine on the 29th of April," former royal butler Grant Harrold told Spin Genie on April 26. "With everything going on with Kate, that won't be a public thing, that's going to be very private. Behind closed doors, I'm sure William will work to make sure she's spoiled."

He added: "It's possible William might cook, he's quite a good cook so it's possible he might do a little meal or something. Again, it's just going to be a private affair between the two of them. Once again, there'll still be an exchange of gifts, I have no doubt they will give each other a gift, and I've no doubt they will exchange cards."

It is currently not known when the future queen will join her father-in-law in returning to public-facing royal duties, but sources close to the princess recently revealed it will likely be "sometime this summer."