• Kate Middleton and Prince William were madly in love, but it was hard to marry an heir to the throne
  • Prince William made sure that Middleton was trained and ready before he married her
  • Prince Harry wanted to leave the royal family, and Meghan Markle enabled him to do what he wanted

Kate Middleton and Prince William took their time before tying the knot, and so Tina Brown praised the couple's relationship in her book.

The Duke and Duchess of Cambridge had known each other for about a decade before Prince William proposed to Middleton. Due to the long wait, some called the duchess "Waity Katie," but the royal biographer praised the future queen consort because it required "a lot of care and strategy to end up married to William."

"They were madly in love all the way through, but … making it from the loving girlfriend to the future queen, that’s an obstacle course," Brown told Page Six when she promoted her new book "The Palace Papers." "And it’s like snakes and ladders. At any moment, she could have stepped on the wrong square and had a snake."

Brown believed that Middleton's mom, Carole, was "very critical" and "helped her avoid the snakes on the board." She also praised the second in line to the throne for picking Middleton as his partner. She also said it was a smart move for Prince William to take his time before proposing to Middleton.

"He was absolutely sure she could handle it before they married," Brown continued. "She was trained. Nobody was deluded like Meghan was, it seems."

She also believed that Middleton played a considerable role in the survival of the monarchy. For Brown, the future of the monarchy depends on Middleton's "slim shoulders."

"It would, I think, crumble at the moment without her because she’s the only modern, beautiful woman who’s well-educated, substantial in herself, who’s actually wanting to commit herself to the rigors of this institution. Not many young women could do that," she added.

Brown, who also served as Princess Diana's biographer, believed it was a blessing that Middleton doesn't think like her sister-in-law. According to her, "If for any reason, she thought like Meghan, ‘I’m out of here, I can do much better,’ it would be a disaster."

Brown also mentioned the Duke and Duchess of Sussex's "mutual addiction drama." For her, their decision to leave the royal family was "wrongly called Megxit." She noted that Prince Harry "wanted out" and Markle "enabled him to do what he wanted." So, Markle should not be blamed for their departure. Brown also believed that without the former "Suits" star, Prince Harry would still be with the royal family.

"If not but for Meghan, he wouldn’t have found a way out because he basically was a man who had everything done for him all of his life. He had never carved a life for himself," she said. "Meghan was very much a self-starter, a self-made successful woman. She knew who to call at Netflix. He wasn’t worldly like Meghan was worldly."

"The Palace Papers" was published Tuesday.

Kate Middleton and Prince William
NASSAU, THE BAHAMAS - MARCH 24: Catherine Duchess of Cambridge attends a meeting with the Prime Minister of The Bahamas, Philip Davis on March 24th, 2022 at his office in Nassau, The Bahamas. The Duke and Duchess of Cambridge are visiting Belize, Jamaica and The Bahamas on behalf of Her Majesty The Queen on the occasion of the Platinum Jubilee. Chris Jackson/Getty Images