Queen Elizabeth II and Prince Philip, Duke of Edinburgh
06/07/2013 AT 01:45 PM EDT
It was business as usual for Queen Elizabeth on Friday.
With her husband Prince Philip, 91, in the hospital
for an exploratory operation, the Queen, 87, continued with her planned visit to open the new BBC headquarters in London.
While observers might expect her to be with her husband of 65 years, for the Queen her work comes first.
"Everything comes second to duty, especially self. People don't understand that these days," says Ingrid Seward, editor-in-chief of Majesty
magazine. "It is always like that."
A royal insider tells PEOPLE, "It reflects a more stoic tradition of British royal rehavior, which is not touchy-feely. Both the Queen and the Duke subscribe to that."
There's also a belief in royal circles that the Queen doesn't like to get in the way.
"She would think, 'What could I be doing, sitting feeling sorry for myself, and what can I do at my husband's bedside?' It's a 'get on with it' philosophy," the royal insider says.
Seward adds, "The Duke hates a fuss, and he would have said to her, 'Now Lillibet, whatever you do, I don’t want you coming to the hospital.' Obviously she will go, but he won't want her to go this early."
As for Prince Philip's condition, the exploratory operation has been completed, and, Buckingham Palace said late Friday, "the results will now be analyzed. At this early stage he is progressing satisfactorily."
At the BBC opening, Her Majesty brushed off concerns about her husband's health, saying, "He's not ill."
Two days before his surprise hospitalization, the Prince was by the Queen's side at Westminster Abbey for Tuesday's Coronation anniversary service
. A guest told PEOPLE, "He was incredibly alert and responding to every detail of the service."
But Philip has been ill several times in the last year and a half. Just before Christmas 2011, he had surgery on a blocked artery
, and he missed a few days of the Diamond Jubilee celebrations exactly a year ago when he was hospitalized with a bladder infection.
He had a recurrence of that the following August.