Supernanny Jo Frost has heaped praise on Prince George and Princess Charlotte for their "poise and grace" at Queen Elizabeth II's funeral, adding the experience will have a "unique impact years later".
The young royals attended the momentous event on Monday alongside their mum and dad, the Prince and Princess of Wales, with their little brother Louis, four, left at home.
The siblings delighted the public during their great grandma's Platinum Jubilee earlier this year and Jo Frost, aka Supernanny, said the eldest pair's "stamina and orderly conduct" in June turned out to be training for the state funeral, watched across the globe.
Taking to Instagram, TV star Jo, 52, said it was a "careful decision for their parents to make" regarding George, nine, and Charlotte, seven, attending the historical event.
She went on: "I believe taking into account their ages and succession to the throne, this historical moment was an absolute must.
"Such emotional life experiences embed memories that do profoundly hold a unique impact years later, one that you will both remember beside your loving nurturing parents."
The Family S.O.S star, addressing George and Charlotte, said: "You did yourselves proud, your poise and grace outstanding... May you remember daily the sweet moments little ones, take comfort from your loving family and heal in your own time."
Jo is known for her main role in Channel 4 series Supernanny UK, which aired between 2004 and 2011, and saw the expert help parents who were struggling with their kids.
George and Charlotte sat on the front row at Westminster Abbey at the state funeral, as the children joined the rest of the Royal Family to say goodbye to Queen Elizabeth.
The Wales' children travelled to the ceremony in the same car as Queen Consort Camilla and their mother, Kate Middleton, who made sure the pair were always close by and felt comforted.
It is understood the royal couple thought long and hard while having discussions with Charlotte and George before deciding they would attend the ceremony.
A nervous-looking Princess Charlotte was comforted by her mother as she entered the Abbey.
Kate could be seen placing a tender hand on her daughter's shoulder as the pair exited the car, and as they approached other people, while Charlotte nervously flipped her hair.
The Princess of Wales was then captured guiding Charlotte past the 2,000 guests - including politicians, world leaders and celebrities - with a reassuring hand on her back.
In a change to the originally suggested formation, the Prince and Princess of Wales walked into the Abbey either side of their children, rather than in front of them, with Kate holding Charlotte's hand.
William was seen showing support to his son, by placing his hand gently on his shoulder as they made their way to the seats passed the Queen's coffin.
A tired George could be seen wiping his eyes as he looked at the Order of Service while sat between his mum and dad.
At one point during the ceremony, Kate placed a gentle and protective hand on George's lap.
