EXCLUSIVE: Steely Kate Middleton 'Determined to Become Just Like Queen Elizabeth' — After Enduring William’s 'Affair', Cancer and Fighting off 'Pesky' Meghan

Courageous Kate Middleton has navigated a difficult period in her life with rumors of her husband's affair, a cancer diagnosis, and sister-in-law Meghan Markle slinging mud from the side-lines and has emerged stronger and even more regal.

As the wife of the heir to the UK throne Prince William, she is a future Queen of England and the trials and tribulations of the last handful of years have helped forge her new-found steely reserve, RadarOnline.com can reveal.

And a Buckingham Palace source said: "Kate knows her time will come soon enough. She will be crowned Queen eventually and that will be her reward for what she has endured over the last few years.

"Following the late Queen Elizabeth Il's example, she has kept calm and carried on since she started dating William more than two decades ago. She has weathered the storm blown up by pesky Meghan and seen her off to a life of anonymity in the States, kept her counsel when rumors swirled around William and now she's beaten cancer."

Her first major engagement after besting cancer was last month when she honored Britain's war dead at the Cenotaph memorial in London and she was poised and calm. The princess became very human to her subjects after her shock cancer diagnosis earlier this year.

Breaking royal precedent, the Princess of Wales even acknowledged her struggle in completing chemotherapy.

"My path to healing and full recovery is long," the 42-year-old said in September. "And I must continue to take each day as it comes."

In 2019, she had remained silent after it was alleged she'd had a mysterious falling-out with her so-called rural rival, Rose Hanbury, hinting that the married 40-year-old Marchioness of Cholmondeley had caught William's eye.

She was relieved when William, 42, secured an injunction from the U.K. High Court to silence the chatter about any affair. "Kate has given so much of herself over the years. She's smiled and stood by the Royal Family and not caused any major scandals. She's supported Prince William and been a gracious, warm and loving wife and mother. She's honored her duties and behaved like a future queen," explains our source. She has also kept 'mum' as rogue royals Prince Harry, 40, and Markle, 43, have repeatedly lobbed shots at her.

In their bombshell 2021 CBS interview, the Duke and Duchess of Sussex alleged that Kate made the Suits star cry in the run-up to Harry and Meghan's 2018 wedding.

In his 2023 memoir, Spare, Harry claimed Kate snapped at his wife for suggesting she had hormonal "baby brain" following Louis' birth.

And he alleged that Kate "grimaced" when the biracial American divorcée asked to borrow her lip gloss before a joint event.

A leaked draft of a Dutch translation of Omid Scobie's 2023 pro-Sussex book pointed at the Princess of Wales as one of the royals concerned about the color of Harry and Meghan's unborn child's skin.

Says the insider. "Kate is used to the proper order of things and was annoyed Meghan couldn't just fall in line and get on with it. Getting on with it has long been Kate's specialty.

"She famously endured taunts of 'Waity Katie' while William delayed his marriage proposal for years, but soon became The Firm's most popular royal after their marriage. "Now, with the monarchy's popularity at a historic low, some royal watchers believe Kate, who earlier this year was called 'the future of the monarchy' by Vanity Fair, is the key to the increasingly controversial institution's survival."

Have a tip? Send it to us! Email RadarOnline.com at tips@radaronline.com.