Perhaps the UK ruler was hoping to clear her mind with a quick jaunt through the English countryside, following what has undoubtedly been a trying few days after her grandson Prince Harry announced his decision to step down from the royal family.
According to UK paper The Mirror, Queen Elizabeth drove only a few kilometres down the road before she pulled in to a field where a shoot was taking place.
A number of guests – including another of the Queen's grandsons, Peter Phillips – were awaiting her arrival.
"The Queen will be feeling very let down and very angry, probably more angry than she felt after [Prince] Andrew's car-crash interview [regarding his friendship with disgraced billionaire Jeffrey Epstein]," the Queen's ex-press spokesman Dickie Arbiter said on TV show Good Morning Britain.
"The Queen didn't know, William didn't know," the former palace staffer insisted.
"[Prince Harry and Meghan Markle] had a brief chat with the Prince of Wales some time ago and he cautioned them to get everything in place before you make an announcement."
As we now know, they allegedly "didn't listen to him", making the announcement prior to planning the logistics of the move in detail.
While the couple have said they intend to be financially independent, they reportedly also wish to maintain their current lodgings at Frogmore Cottage.
However, in the proposed plan for the couple's shift out of royal life that Harry emailed to Charles, "the money didn’t stack up," reports UK newspaper Evening Standard.
"Taxpayers would still be forking out millions of pounds for round-the-clock security, and the tax perks that go with a grace-and-favour home.
"The Duchy of Cornwall would still be providing the bulk of the income, hardly most people’s definition of financial independence."
Meanwhile, Charles and Harry's brother Prince William are said to be "incandescent with rage" over the Duke and Duchess of Sussex's announcement that they will step down as senior royals, splitting their time between America and the UK.