“Sarah found herself denied access to the big house at Sandringham," Ms Boycott continued.
“Determined to be close to the children, she elected to stay at the gate house.
“Cars were sent for Eugenie and Beatrice early in the morning.
“Andrew entertained his daughters, leaving his wife alone like a dog in quarantine.”
Ms Boycott later went on to describe the heartbreaking comment made by Princess Beatrice and Princess Eugenie on Christmas Day in 1996: “She reminisced about the nightmare Sandringham Christmas and the children enquiring: 'Why is mummy not allowed in the big house any more?'"
Despite Fergie being banished from the family home at Sandringham, Ms Boycott reveals Queen Elizabeth remained a tentative supporter of her former daughter-in-law.
"The Queen remained astonishingly tolerant," Ms Boycott wrote.
"Despite the appalling publicity her daughter-in-law had brought on them all, she turned up in the afternoon for a few private seasonal whiskies.
"Everyone else in Sarah's life might have been throwing her to the wolves, but her mother-in-law offered kindness and support – as she still does."