The US tabloid adds that Camilla's previous blowouts with the Royal Family were partly to blame for the new split.
"The royals are convinced Camilla is nuts!" a source says.
"She's had confrontations with Prince Harry's new wife, Meghan Markle, attacked Prince William's wife, Kate Middleton, and even Prince Philip."
The insider adds, "She's been fighting the entire family."
Camilla, since announcing her shock decision, has been on a "warpath", GLOBE adds.
"She's threatened to reveal all the royal family's darkest secrets," and has reportedly demanded a $400 million payout.
"There are frantic talks going on behind closed doors at Buckingham Palace, trying to negotiate some sort of face-saving compromise."
"But, you know Camilla will play hardball.
"There's nothing worse than a wannabe queen scorned, and the royals are bracing for one of the nastiest - and most expensive - royal bust ups in history."
The Royal Family is yet to respond to GLOBE's claims.