The late Queen Elizabeth II reportedly tried to convince Meghan Markle to mend her relationship with her father, Thomas Markle. However, despite the monarch's efforts, Prince Harry's wife has remained estranged from her dad.

Royal expert Katie Nicholl made the claim in her upcoming book, "The New Royals." But before she made this revelation, earlier reports stated that aside from Queen Elizabeth, King Charles III also urged Meghan Markle to make amends with Thomas Markle.

Nicholl wrote that Her Majesty saw how bad the relationship between the father and daughter was. So, she spoke to her granddaughter-in-law about it and tried to persuade her to talk to her dad.

A royal source told Nicholl that the queen believed their ordeal was "badly handled." If it were only done differently, then things might have been better.

For starters, Thomas Markle, a former lighting director for TV shows, was about to walk his daughter down the aisle at her wedding at St. George's Chapel, but it didn't happen. Photos of him getting ready for his child's special event, being measured for his suit and reading books about the U.K., even surfaced.

However, he later revealed the photos were only staged with the help of a paparazzo. He then withdrew from the wedding and underwent heart surgery.

Despite what happened, Thomas Markle said he would always regret not attending the ceremony and holding her daughter's hand. The relationship between the two further deteriorated after Meghan Markle accused him of leaking the private letter she wrote after the nuptials.

In addition, Nicholl claimed Queen Elizabeth also saw Prince Harry's decision not to travel to Mexico to meet his then-future father-in-law as a mistake. She believed her grandson should have met Thomas Markle, finding it unfortunate that it didn't happen.

Elsewhere, veteran biographer Tom Bower wrote in his book, "Revenge: Meghan, Harry, and the War Between the Windsors," that aside from Queen Elizabeth, King Charles also strongly encouraged Meghan Markle to repair her relationship with her dad.

With her alleged refusal, the new monarch reportedly felt "irritated." The mother and son even urged the Duchess of Sussex to fly to Mexico to see her father in person, but she refused, upsetting the two senior royals.

Allegedly, Meghan Markle said that it was unrealistic for her to discreetly fly to Mexico, arrive at his doorstep without everyone knowing, to a location she had never visited or known. She also found it impossible to talk to Thomas Markle privately without causing a frenzy or getting the media's attention that could embarrass the royal family more. As Queen Elizabeth II wanted the former actress to make amends with her father, she also wished the same for Prince Harry and the royal family.