It was a text from one of my daughters at 12.34pm that first alerted me to the sudden deterioration in the Queen’s health on Thursday.

“Have you heard what’s happened in the Commons? Everyone’s passing notes around, lots of grave expressions. Think the Queen is dying.”

I was at home and immediately switched on the television. The BBC had just reported the palace’s ominous statement announcing that the Queen’s doctors were “concerned” for her health and “recommended she remain under medical supervision”.

That, and then the news that her closest family were rushing to her bedside in Balmoral, served as a warning to the nation to prepare for the worst.

At 96, and with her frailty all too obvious as she welcomed Liz Truss, her 15th prime minister, on Tuesday, the monarch’s decline should not have been a surprise. But, as Boris Johnson put it, we had come to believe, like children, that she would just go on and on.

That she was mortal after all stopped the country in its tracks. At Westminster, MPs lost interest in the debate about the new energy policy. On the BBC, all normal programming was suspended and the presenter of the day made way for Huw Edwards, arriving in black suit and tie. 

I sat glued, switching between the news channels but mainly staying with Huw, who was soon joined by the BBC’s veteran royal correspondent Nicholas, let’s call him Nick, Witchell, as events unfolded.

Shock and sadness at the Queen’s imminent passing – I don’t think there was any doubt about the gravity of the situation – were on hold over the course of six hours, while the nation waited for further bulletins from the palace.

Just as the government’s arrangements for this inevitability, codenamed Operation London Bridge, had been honed to the last detail over many years, so had the BBC’s coverage, and the exchanges between Huw and Nick were well rehearsed.

Even so, there was confusion – were both the Sussexes heading to Deeside (Meghan “might not be terribly warmly welcomed” said Nick) or just Harry? Which senior royals were on the RAF plane heading for Aberdeen airport mid-afternoon? 

In particular, there seemed to be a wobble, hard to pin down exactly but definitely before 3pm, when the tone changed. News rooms, including no doubt the BBC’s, were expecting an update around then, possibly bringing the grim news of Her Majesty’s death. 

But the deadline passed, the palace was silent, and Huw and Nick had to keep the show on the road, without spilling any beans prematurely.

I admit, though my love for the Queen has been unconditional, that I became as engrossed, as the hours passed, by the reportage as by the awful omens from Balmoral.

How many different ways can you express fears for a beloved sovereign’s wellbeing – and report on the story for which you have been in training half your professional life – while maintaining an omerta before the unsuspecting public?

“We are in unknown territory…there have been clues over the last few days that her health was heading in a negative direction,” said Nick, quickly adding that her reign “is not over and we’ve nothing to suggest that it is”.

“She has done – and continues to do – a magnificent job,” said Huw, who had to remind himself, and us, to hope for the best against the odds.

When, near six o’clock, he interrupted a colleague with, “Chris I’m going to have to stop you there, I’m afraid we have a dreadful…”, my household, along with the rest of Britain, held its breath but Huw just mentioned “problem with the mic”.

By now, William had driven his two uncles, Andrew and Edward, with wife Sophie, through the gates at Balmoral, a close-up revealing four drawn, devastated faces.

Nick was practically begging for an update: “Buckingham Palace will have to say something, but we have no indication that they will.” He and Huw both deserve Oscars for best performance in delivering a running commentary on the death of the Queen (while not mentioning her death).

The confirmation when it eventually came, at about half past six, packed a hefty emotional punch, in the studio and at home. 

As a Windsor girl, who had trooped to the Long Walk, in school blazer and white gloves, to wave to the Queen in her open carriage en route to Ascot, I had dreaded this moment.

Like many who were not actually acquainted with Her Majesty, I nevertheless regarded her as a familiar presence, and had dined out on my family’s unlikely role as extras throughout her reign. 

We had a special bond, from my father’s meeting with the then Princesses Elizabeth and Margaret Rose when King George VI’s tour of southern Africa stopped at his school near Bulawayo, to my South African mother securing a coveted invitation to the coronation in 1953.

Growing up in the shadow of the castle would bring out the royalist in all but the staunchest republican, but there was no argument in my home. The Queen represented stability, safety, goodness and grace, the embodiment of why we had emigrated to Britain from apartheid South Africa in the Sixties.

Her long life somehow provided a link to that past, and in a poignant, for me, footnote, we lost her on the anniversary of my father’s death. That’s my story, and my excuse.

Around 6.35pm on Thursday I found my husband sobbing in the kitchen. He had met the Queen twice, very briefly, in line-ups. “So, you knew her too,” I said. We opened champagne and toasted her, as you do for a dear friend just departed.