The source went on to say that the duchess is “heartbroken” by the state of William and Harry’s once-close relationship, but she remains an “eternal optimist” for the future.
“It’s her firm belief that one day Harry will snap out of his trance and be his own man.
“If she can somehow get the boys to make peace – even temporarily – it would be the greatest birthday gift William could wish for.”
William and Harry’s well-documented feud began around 2016 when the latter started dating Meghan Markle.
While the duke was besotted with the actress, apparently William had his reservations about how quickly things were moving between the couple - and he told his little brother as much once Meghan had returned to her home country of Canada.
According to The Sun, a well-placed source revealed: "William told his brother that they knew nothing about her background, her intentions, what she was really like.
"He just wanted to stress that becoming part of the Royal family is a massive undertaking and the pressure and scrutiny is unrelenting. Was Meghan the right one?"
Suffice to say, William's reservations didn't go down too well with Harry, who allegedly "went mental" in his defence of Meghan.
The same source claimed: "He accused his brother of trying to finish his romance before it had begun. The brothers' relationship has not really recovered."
From there, it seemed things only got frostier between the brothers, with the Duke of Sussex telling ITV in 2019 that he and the future king were “on different paths”.