The Queen's aide Angela Kelly could play a historic role at Prince Philip's funeral.
Ms Kelly - who is thought of like a 'second sister' - is reportedly among the few people in Her Majesty's Windsor 'bubble' who could sit next to her as the Duke of Edinburgh is laid to rest on Saturday, April 17.
It comes as royal sources confirmed to The Telegraph on Tuesday that due to Covid rules, the Queen faces the prospect of sitting by herself unless she asks a member of the bubble to join her.
However, royal biographer Angela Levin believes the stoic monarch would prefer this as "she doesn't want to look as if she's falling apart."
But, she could choose to turn to one of her most loyal and discreet aides, Ms Kelly, to be by her side as she mourns her husband of 73 years.
The pair have a friendship like no other within the Royal Family.
Humble Scouser Ms Kelly has worked for Her Majesty for more than 25 years and went from living in a council house to being her right-hand woman.
Ms Kelly's official title is personal assistant, adviser, and curator (jewelry, insignias, and wardrobe), but behind closed doors, she is a trusted confidante, friend and almost like a sister to the Queen.
She will no doubt have been a constant source of strength and comfort to Her Majesty following the death of Prince Philip at the age of 99 on April 9.
This week, she was spotted on the royal estate in Windsor on the phone and uploading items from a car.
Before lockdown, the pair loved nothing more than having a natter over a cup of Darjeeling tea at Ms Kelly's cosy grace-and-favour Windsor home, gifted to her by the Monarch.
And it was said that when the Queen told staff she was "stepping out for a bit" it was actually royal code for her popping to see Ms Kelly.
When together, they could be heard down the corridors roaring with laughter.
"We are two typical women," Ms Kelly told The Telegraph in a rare interview in 2007.
"We discuss clothes, make-up, jewellery. We say, 'Would this piece of jewellery look nice with that outfit?', and things like that."
But their close relationship has in the past reportedly caused jealousy among other members of staff, with Ms Kelly joking: "I don't have any more room for knives in my back."
She added: "I don't know why the Queen seems fond of me - because I don't give her an easy time!"
But so strong is their bond a book, called The Other side of the Coin, was published about their friendship after the Queen, who turns 95 next week, gave Ms Kelly "extraordinary permission" to spill private details.
In the past, Ms Kelly has only given a handful of interviews but when she has spoken out publicly, she has gushed about her unwavering affection for her boss.
She has described how much she "adores" and is "so proud of her".
Although Ms Kelly insists she is not a replacement for the Queen's sister Princess Margaret, who died aged 71 in 2002, they are thought to have grown closer as a result.
Speaking of their friendship, Ms Kelly said: "I am not there to replace her mother and her sister.
"I do worry about her and care about her. But we also have a lot of fun together. The Queen has a wicked sense of humour and is a great mimic. She can do all accents - including mine."
Ms Kelly also previously revealed she reminds herself "she is not 'my' Queen, she is everyone's and so I have to share her."
A source claimed the Queen is "noticeably more relaxed" when Ms Kelly is around as she "has the Queen's best interests at heart, she is fighting the Queen's corner."
While Ms Kelly previously said: "I come from a humble background and I hope to stay humble.
"But I hope the Queen and I grow old together."
And the Queen, who made Ms Kelly a member of the Royal Victorian Order, once told her: "You and I do work well together. I think we are a good team".
Meanwhile, talkRADIO breakfast show presenter Julia Hartley-Brewer spoke of the prospect of the Queen sitting alone.
She said: "The thought of a woman in her 90s losing her husband of more than 70 years not being able to have her sons or her daughter have their arm around her during a private ceremony for her husband's loss, because that's against the law, is so disgusting and repulsive I can't even believe I'm saying those words out loud."
But royal biographer Angela Levin believes the Queen would not find issues with this.
"I can't believe that the Queen who believes in the stiffest of upper lips would want anybody sitting next to her," she said.
"I think if she did, they would have arranged something. There are members of the family and her staff who have been very close to her during the pandemic. And I think one of them would have been invited along.
"I think Sophie, who is married to Edward the Queen's youngest son, is very close to the Queen. It's been mentioned that the Queen thinks of her like her own daughter and she's been there so often I can't see that she wouldn't be allowed to sit next to the Queen should she want it.
"I think it would be easier for the Queen to keep this stiff upper lip. She likes to be very disciplined. She doesn't want to look as if she's falling apart."
Ms Levin continued: "In a way sometimes it's easier to be by yourself than with someone who's close to you, who loves you, then you feel like you let all the emotion out."