According to Finding Freedom, the royal biography by Omid Scobie and Carolyn Durand, the Prince of Wales has a "framed black-and-white photo of himself escorting his daughter-in-law at his Clarence House residence".
The photo was taken at Meghan's wedding to Prince Harry where Prince Charles stepped in to walk her down the aisle at short notice when her father was unable to attend.
Prince Harry has previously told the BBC that when he asked his father to walk Meghan down the aisle "he knew it was coming".
"He immediately said, 'Yes, of course, I'll do whatever Meghan needs and I'm here to support you,'" Harry said.
"For him that's a fantastic opportunity to step up and be that support, and you know he’s our father so of course he's gonna be there for us."
Finding Freedom reveals one of the reasons Prince Charles is so fond of his daughter-in-law is because of her "confidence".
"She's bright and she's self-aware, and I can see why they've struck up a very quick friendship," a source told the authors.
A friend of Meghan's also shared that Meghan has "found such a supportive and loving father in Charles, which has really changed her life for the better".
The book also details the moment Prince Harry introduced Meghan to the Queen and other members of the royal family.
An extract in the book reveals Meghan met the Queen in 2017 at her private apartments, "Despite a very brief encounter with Her Majesty earlier in the year ("she and Harry literally bumped into her," a source laughed), Meghan was still nervous to meet his grandmother – it would be the first time she was sitting down with the monarch as Harry's fiancée."
It comes as the pair picked up an incredible home in Montecito, California for a jaw-dropping AUD$20.4 million.
See photos of the gorgeous home here.