Lady Louise Windsor was baffled to learn that the Queen is actually her grandma.
Louise grew up with a very down-to-earth relationship with Her Majesty and had no idea her grandmother was the monarch - until her friends at school pointed it out.
Lady Louise and her brother James Viscount Severn, 14, are the monarch's youngest grandchildren - and the Queen is understood to be very fond of them.
The family lives at Bagshot Park, a short drive away from Windsor Castle, and they spend a lot of time together.
During an interview recorded ahead of the monarch's 90th birthday, the Countess of Wessex revealed her children affectionately nicknamed the Queen ‘grandmama.’
Sophie, 56, said her daughter had ‘no concept’ that her grandmother was famous when she was younger.
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She told Sky News : “I mean Louise had no concept really that the Queen and her grandmother were one and the same person.
“It wasn’t until she was at school that other children were mentioning it and saying, ‘Your gran is the Queen.'
“And she’d come home and say, ‘Mummy they say that Grandmama is the Queen.’ And I said, ‘Yes,’ and she said, ‘I don’t understand what they mean.’”
Prince Edward, 57, also said he did not realise his mum was the monarch until the age of five or six.
He said: “I can’t necessarily remember when that realisation was there.
“When you grow up in that family and in that environment, that’s just what your parents do.
“It’s been much more interesting watching our children growing up, and watching our children trying to work out what this is, and how that works. It was probably not until five or six I think.”
It has been reported that Louise has an artistic flair and a love of drawing, so the Queen allowed her to look through some of the collection of Queen Victoria’s Highlands sketches, which are kept at Balmoral.
An insider said: "The Queen loves the fact that Louise and James [Louise's younger brother] relish their time at Balmoral, and she has become particularly close to Louise, who seems to have become her favourite grandchild, closely followed by James."
During the summer break at Balmoral, Louise has also helped to look after William and Kate's children .
A source said: "Louise loves drawing and sketching and was very patiently trying to get Charlotte to do pictures of rabbits and deer."
Louise is also said to have a close relationship with Princess Charlotte, six, despite the 11-year age gap between them.
Last month, an expert claimed that Lady Louise could take on royal duties to help out the dwindling number of working royals.
The young royal, who turned 18 in November, kept "a rather charming but low profile" while growing up, but she might decide to get involved in the work of the Royal Family more in the near future, royal commentator Richard Fitzwilliams told the Express .
The expert said: "With the number of working royals now fewer and most being from the older generation until George, Charlotte and Louis are able to take on royal duties, there may well be charitable ventures she may wish to support in future years and from that may follow occasional royal engagements."
