As King Charles III faces a battle with cancer, the monarch finds solace in knowing that his son, Prince William, and daughter-in-law, Kate Middleton, are well-prepared to take the throne when the time comes. According to an insider who spoke with OK! Magazine, the late Queen Elizabeth II "would have been so proud of Kate," and King Charles "definitely is."

"It gives him great comfort to know that she and William are prepared to take the throne," the source revealed, emphasizing that the Princess of Wales has been training for this moment her entire adult life.

Since the early days of her relationship with Prince William, Kate has "learned early on to exercise remarkable discretion and composure," the insider noted. "And in two decades, she has rarely made a misstep. She always toes the family line."

The source went on to praise Kate's ability to honor the legacy of the late Queen Elizabeth II while also subtly modernizing the way things are done within the royal family. "Kate followed Elizabeth's lead in every way and has vowed to honor her legacy," the insider said. "But Kate has also managed to subtly but firmly modernize the way things are done at the Firm, without ruffling feathers, like the late Princess Diana and Meghan Markle did. She's a natural."

The insider's comments come as both King Charles and Kate Middleton face health challenges. In January, the King underwent prostate surgery, but a few weeks later, he revealed that he had been diagnosed with cancer. A palace statement confirmed that the monarch had "commenced a schedule of regular treatments" and would continue to undertake state business and official paperwork as usual during this period.

Despite rumors circulating about the King's health, Buckingham Palace later clarified that while His Majesty is "not yet clear of cancer and is still undergoing treatment," his medical team is "pleased with the progress made so far" and "remain positive" about his recovery.

Meanwhile, Kate Middleton, who was also diagnosed with cancer in March, is said to be nearing the end of her treatment and responding positively, according to the source, as reported by In Touch magazine. The Princess's top priority has been ensuring that her children - Prince George, Princess Charlotte, and Prince Louis - feel safe and secure during this challenging time.

As a testament to the faith King Charles has in his daughter-in-law, the monarch recently appointed Kate as a Royal Companion in the Order of the Companions of Honour, making her the first member of the family other than the monarch to be part of the elite group. This historic move is seen as a significant step toward Kate's future role as queen.

"Charles chose to honor Kate now to reward her for her resilience over these past few months as she's battled cancer amid intense public scrutiny," the source explained, "and to show how much faith he has in her to keep calm and carry on, just as his mother did."

Looking ahead, the insider suggests that one of Kate's first priorities as queen will be to show unity within the royal family. "She could reach out to Prince Harry in an attempt to make peace in the family," the source said, adding that while Kate and Meghan Markle may never be on warm terms, the future queen is "determined to be civil," following the example set by the late Queen Elizabeth II.