Kate Middleton is said to be looking forward to Queen Elizabeth II's Platinum Jubilee celebrations because she sees it as an opportunity to mend her relationship with Meghan Markle and Prince Harry.

Royal author Ingrid Seward said the Duchess of Cambridge "will not forget" how her sister-in-law treated her after their explosive Oprah interview in March last year. In it, the Duchess of Sussex clarified rumors that she made Prince William's wife cry in the leadup to her wedding to Prince Harry.

She claimed it was the other way around and that the 40-year old said something that upset her and made her cry. Kate Middleton made up for her mistake with flowers and Meghan Markle even called her a "good person."

However, Seward claimed that the mum-of-three may never forget how the Duchess of Sussex made her look with that revelation. But "she knows there is no point in prolonging a feud that has the opportunity of being repaired. The Platinum Jubilee is just that chance."

"If necessary, Kate will also try to be the peacemaker between William and his brother Harry. Being royal is all about appearances, not private feelings," the royal editor told the Mirror adding, "It always has been throughout history. It is what the Queen has spent 70 years perfecting and she expects her family to do the same."

The author of "Prince Philip Revealed: A Man of his Century," said that Kate Middleton and Meghan Markle will appear united in public. The Duchess of Cambridge "will be cordial" to her sister-in-law and she will surely "be photographed kissing or hugging her."

"She has to - that is part of her job. Her private feelings have to remain just that," Seward explained.

The Duke and Duchess of Sussex not only made allegations about Meghan Markle but against The Firm itself. They claimed that one of the senior royals is racist and accused the institution of turning their backs on the duchess when she sought their help for her suicidal thoughts.

Seward said that despite the hurt brought by the Oprah interview, Queen Elizabeth II, Prince Charles, Prince William, and Kate Middleton know there is "nothing to gain" from shutting Prince Harry and Meghan Markle out of the Platinum Jubilee celebrations.

The British royals
Prince Charles, Prince William, Kate Middleton, Meghan Markle, Prince Harry Photo: AFP / Paul ELLIS