"'The cottage was a big deal,' she said. 'The Queen's entrance into the gardens is right next to their cottage.
'It is essentially her back yard, her solitude, and her privacy. She was giving that up in gifting Harry and Meghan Frogmore Cottage. We all thought it was very big of her. She said, 'I hope they'll respect it'.
"In April 2019, the couple finally moved in. Then, the following month, Buckingham Palace announced a still more significant departure: Harry and Meghan were moving their royal household – effectively their office – from Kensington Palace to Buckingham Palace."
It was a significant move, particularly as it marked the end of William and Harry's "double act" - and was "deeply disappointing" for the Queen, Nicholl writes.
The royal editor has published one of two books which make bombshell claims about the royal family.
The second, Courtiers: The Hidden Power Behind the Crown by Valentine Low, claims Meghan believed marrying Prince Harry would make her the "Beyoncé of the UK" before realising she didn't like the strict rules of life as a royal.
The book also alleges that the Queen was forced to put her foot down over Megxit, telling the Sussexes that they were "either in or out" at the Sandringham summit where the royals met to decide Harry and Meghan's future.