The decision that Eugenie, who is expecting her first child in the new year, along with her husband Jack Brooksbank would move into the property reportedly wasn’t discussed with the royal family.
A source told the Sun on Sunday: “Senior royals were initially blindsided by the idea for Harry and Meg to let Eugenie and Jack move in.
“Obviously the Queen was told after the couples had spoken about the plan.
“But it is very much a deal done between Harry, Meghan, Eugenie and Jack. There is a close bond between them.”
While the Duke, 36, and Duchess of Sussex, 39, make their life in California an insider claimed they have had their possessions shipped over to them after a removal company “cleared out the cottage”.
A source previously said: “Emptying their home and handing over the keys is a pretty strong sign Harry and Meghan have no plans to return.
“It appears they are tying up loose ends as they plan to extend their stay in the US perhaps permanently.”
And Eugenie, 30, and Mr Brooksbank, 34, reportedly moved into the five-bedroom home a couple of weeks ago.
There probably isn’t much to do by way of redecoration for the couple after Harry and Meghan spent £2.4million from the Sovereign Grant on renovations on the property.
This became a source of controversy once they made the decision to step down as Senior Royals themselves in March and in September they announced they had paid the money back in full.
The expectant parents had been living at Ivy Cottage at Kensington Palace but moving into Frogmore Cottage the Princess will live just four miles away from her parents Prince Andrew and Sarah Ferguson, at Royal Lodge, Windsor.
A Buckingham Palace spokesman said: “Frogmore Cottage is the private residence of the Duke and Duchess of Sussex and as such any arrangements are a matter for them.”