Kate Middleton is preparing for Queen role 'sooner than expected'

King Charles III's health recovery is reportedly taking longer than expected. And as a result, rumours have been rife that both Prince William and Kate Middleton are secretly being prepared for a possible ascension to the throne.

It was no surprise that, following her father-in-law's May 2023 Coronation ceremony, the Princess of Wales' royal responsibilities would sky-rocket in both frequency and importance.

After all, the celebration didn't only mark Charles' ascension following the death of Queen Elizabeth II, but the gradual move of her own husband towards the top of the British monarchy.

For the remainder of 2023, Kate was ceaselessly photographed making health and mental wellbeing centre visits, meeting with educational leaders, attending red carpet soirees and bringing her children along to important scouting events.

What both the royal family and the nation failed to expect, however, was less than a year later, mother-of-three Kate would be diagnosed with cancer, for which she'd have to undergo chemotherapy for several months.

As such, she understandably removed herself from the spotlight - and her royal duties - for a brief period to focus on her health and her family.

Thankfully, however, just six months after breaking the initial news of her March diagnosis, Kate revealed in a sweet September video that she'd concluded her treatment and was on the mend.

According to one commentator, however, the Princess' recent return to royal duties has been somewhat of a baptism of fire.

Both Charles and Kate were diagnosed with cancer earlier this year (Karwai Tang/WireImage)

As well as picking up where she left off with her prior responsibilities, she's reportedly been preparing for the possibility of taking to the throne as Queen.

Sally Bedell Smith told press this week that, following his own cancer diagnosis - which he revealed in February - King Charles is yet to fully bounce back.

"Although the King is carrying out his duties with typical determination, he has had to accept limitations during his cancer treatment." the royal expert explained.

"As a result William has been taking on more responsibilities, and he and Kate have been preparing for their future roles sooner than they would have expected."

Proof of William and Kate having stepped up came earlier this week, when the future King met with several world leaders - including presidential elect Donald Trump - in Paris to mark the reopening of the Notre Dame Cathedral.

Kate and William are said to be stepping up (CHRIS J RATCLIFFE/POOL/AFP via Getty Images)

This is a responsibility that would have previously fallen onto his 75-year-old father, who underwent surgery on an enlarged prostate in January, with the palace later telling press that the procedure was 'corrective' and that his condition was benign.

Another royal source told PEOPLE Magazine this week of the responsibilities that have fallen onto the Prince and Princess of Wales as a result of Charles' ongoing health woes.

"They are next in line for the biggest job of their lives, and of course, Kate's health has taken priority, but it's also allowed everyone to take a step back and figure out what's important right now," the source claimed.

Another palace insider reportedly told press earlier this year that the preparations had actually been in place behind the scenes since Charlies' Coronation.

"It is something the institution is always mindful of," they said. "It is an institutional preparedness."