Sarah, also known worldwide as Fergie, sent the Queen’s younger sister a bunch of flowers to make amends in the weeks after her split from Andrew was leaked to the press in 1992.
But a furious Princess Margaret sent the flowers straight back to Sarah along with a scathing note, according to a recently unearthed 1997 clip.
Speaking in 1997 documentary ‘Fergie: Downfall of the Duchess’, Judy Wade, writer and royal journalist, said: “The Duchess of York had sent flowers to Princess Margaret with a little note, no doubt trying to renew their once good friendship and the flowers had been sent straight back with a note from Princess Margaret saying ‘how dare you send me flowers, have you ever considered what damage you have done to the Royal Family?’
“And I thought that was the worst example of a pot calling a kettle black in history because in the 50s and 60s Princess Margaret was notorious for her behaviour, it was totally out of keeping with her position.
“So I think Princess Margaret was cruelly unfair to do such a thing when it was a kind gesture from Sarah, very well intentioned, and i think that indicates exactly how the Royal Family treats somebody who steps out of line, except if they’re born royal.”
Aware of her sister’s hostilities towards Sarah, the Queen offered her troubled daughter-in-law support following her split.
The Queen is said to have invited Fergie to stay in a nearby farm house for the Christmas holidays so she could see her grandchildren, Princess Beatrice and Princess Eugenie.
The monarch is said to have told her daughter-in-law: “If you come, you know, maybe we can meet secretly and at least I can see my grandchildren for Christmas”.
Allan Starkie, author of ‘Fergie, Her Secret Life’, said: “Over the years, the Duchess was convinced that the Queen was hoping the Duchess’ fight against this bureaucracy that had taken over the monarchy would be a successful one.
“The Duchess began to get the feeling that the Queen was a prisoner in her own family, secretly rooting for Fergie to be this new light, that kind of cleared up all this darkness.”
However just years later, Sarah officially left the Royal Family when she and Prince Andrew divorced in 1996 after pictures emerged of her receiving a toe-sucking from her lover and oil tycoon John Bryan.
Sarah Ferguson was staying at Balmoral when the images were published, and the Windsors came across them in the morning newspapers at the breakfast table.
Prince Philip was said to be livid when the pictures emerged and has never forgiven the Duchess of York for the series of scandals that she has put the family through
But the pair will reunite when Sarah and Prince Andrew’s youngest daughter Princess Eugenie ties the knot to Jack Brooksbank in October.
Meanwhile, Prince Philip and Princess Margaret were not the only members of the Royal Family to make their dislike of Prince Andrew’s wife clear.
Princess Anne once described Sarah as the “outsider” of the firm, which sparked the two women to have a “very, very frosty relationship”.