Today (November 8) is a significant royal birthday - but there's little public fanfare for the Queen's youngest granddaughter turning 18.
Lady Louise Windsor, born in 2003, is seventh of the Queen's eight grandchildren, and is the daughter of Prince Edward and Sophie, the Earl and Countess of Wessex. Currently 16th in line to the throne, she enjoyed a quiet childhood growing up at Bagshot Park, close to Windsor Castle, and was close to Prince Philip, who was hugely supportive in her chosen sport of carriage-driving.
Lady Louise is in her final year at St Mary's School Ascot, and is currently taking English, History, Politics and Drama A-levels.
But while the reticent royal has stayed under the radar, protected by her parents along with her younger brother, James, Viscount Severn, 13, now she's 18, she could choose to become a working royal, undertaking formal engagements and patronage of charities.
Her mum Sophie is an increasingly well-recognised royal face as she takes on more official duties for the Queen. She is patron of over 70 charities and organisations, including Childline and the London College of Fashion, and attends over 200 engagements every year.
She is also patron of the charity Wellbeing of Women, and has recently spoken openly about menopause and highlighted campaigns to accommodate menopausal women in the workplace more effectively.
Watch: Lady Louise Windsor to inherit Prince Philip's carriage and horses
However, unlike more high-profile royals, the Wessexes are seldom seen out and about with their children, having prioritised their right to a normal, private upbringing.
In fact, Sophie has admitted that it was a bit of a "shock to the system" for the small Lady Louise to discover that her grandmother was the Queen. “I don’t think she had grasped that perhaps there was only one Queen.
"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’."
Aside from being a bridesmaid at the wedding of her older cousin Prince William's wedding to Kate Middleton in 2011 and going with her parents on a tour of South Africa in 2015, Louise has rarely made public appearances.
She recently charmed audiences with a sincere tribute to Prince Philip, to whom she was close, saying" "The Duke of Edinburgh has been so involved in my (carriage) driving, but it's slightly scary as he invented the sport pretty much.
"But there was certainly an element of making my grandfather proud and honouring him by taking part in the award that has been so much of his life's work. And I definitely hope that I have made him proud... it's incredible to have learned first-hand from him and it definitely made us closer, I think."
She is also much in demand for looking after the smaller royals, babysitting for Kate and William when they're at Windsor, and helping Charlotte to draw.
But while Louise has grown up in the bosom of the The Firm, and is supposedly one of the Queen's favourites, she has never used a royal title. However, as Prince Edward's daughter, she is now entitled to use 'HRH,' though her mother thinks it's 'unlikely' that she will.
"We try to bring them up with the understanding they are very likely to have to work for a living," she told The Sunday Times.
“Hence we made the decision not to use HRH titles. They have them and can decide to use them from 18, but I think it’s highly unlikely.”
Watch: Prince Philip's death has left 'giant-sized hole in royal family' says Sophie Wessex
Louise would technically need the Queen's permission to use the title, though it's likely the Monarch would happily give it.
Louise is more likely to postpone any royal duties until she's 21, after she's left university - and she may choose instead to work for a living.
Sophie recently said, ""I wouldn’t force her (to go), but if she wants to. She’s quite clever... But I have to let her live her life. It's not mine to live. I can only equip her the best that I can, and then she has to make her own choices."
Louise may even choose to focus further on carriage-driving.
Speaking about Prince Philip for a documentary in September, she said, "'When we would go carriage driving, he would take me on a different route every day, I do not know how he managed to do that, and tell me all sorts of anecdotes about anything and everything.
"He is honestly one of the most interesting people I have ever met."
Watch: Wessexes join beach clean volunteers