"This is certainly how the people in St.James's Palace who worked with Peat during those first few months viewed the situation," she wrote, as many people thought it unsuitable that Charles would marry a divorcee.
However, it became clear that Prince Charles would never give up Camilla.
"The Prince would never give up Camilla, no matter what, and so Peat rapidly changed tack and with the zeal of the freshly converted, became the loudest, fiercest advocate of their marriage," she wrote.
Last week, it came to light that Camilla, The Duchess of Cornwall, has donated to an Australian bushfire charity.
Non-profit organisation GIVIT announced on Twitter that Camilla had dug deep to help those affected by the devastating Australian bushfires.
"Thank you to The Duchess of Cornwall for embracing GIVIT’s way of giving to help bushfire-affected Australians. We’re humbled & excited to share @ClarenceHouse has generously donated to our #AustralianFires Appeal. Thanks also to all who have already donated to our various appeals – Every #donation helps a person in need”.
The news comes after her husband Prince Charles delivered a video message expressing his despair at Australian’s who have been impacted by the bushfires.
“I fear this is a hopelessly inadequate way of trying to get a message to all of you that both my wife and myself are thinking of you so very much at such an incredibly difficult time and in such impossible and terrifying circumstances,” he said.