She arrived by helicopter on Friday evening and is expected to stay there until Monday, July 19.
The monarch was photographed driving a Land Rover around Wood Farm Cottage and appeared to be accompanied by John Warren, his blood supply and racing advisor, reports The Sun.
There was another male companion who was seated in the back of the car.
This is her first visit to the chalet, located on the edge of the Sandringham estate, since her husband died in April at the age of 99.
It was in this residence, near the Norfolk coast, that Prince Philip enjoyed a quiet retirement.
Many of his personal belongings are believed to be located here.
The Duke of Edinburgh retired from public life in August 2017.
The cottage became his retreat, where he read history books and biographies and enjoyed painting watercolors, while the Queen continued to work at Buckingham Palace.
On top of that, the Duke would entertain family and friends, including regular visitor Penny Brabourne, Countess Mountbatten of Burma, who shared her passion for horse-drawn carriage riding.
Philip taught the Countess to ride a horse-drawn carriage in 1994 and she has become his regular sports companion with the oft-pictured couple indulging in the exhilarating pastime.
The Countess was also one of the few mourners to attend Philip’s funeral in Windsor due to Covid restrictions.
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The Queen and Philip were last together at the Norfolk Cottage in September.
They scrambled to Windsor Castle for lockdown and isolated with a handful of employees in what has been dubbed “HMS Bubble”.
In photos of the Queen that emerged on Sunday, she can be seen wearing a white top with pink rose prints and a green waistcoat as she got behind the wheel of her car.
Horses were seen being driven around the estate’s Commodore Yard stables.
This is where the process of breaking the yearlings takes place.
The Queen has owned hundreds of racehorses over the years and has won over 1,600 races to date.
In addition to thoroughbreds, she is also known to breed Shetland ponies at Balmoral in Scotland and Fell ponies at Hampton Court.
The Queen only started riding at the age of four when she was given a Shetland pony, named Peggy.