Many avid royal fans will remember Lady Louise's sweet smile from Duchess Catherine and Prince William's iconic 2011 royal wedding.
To this day, photos of the angelic blonde seated in a horse-drawn carriage next to her cousin Prince Harry still warm our hearts.
Now, the young royal has celebrated her milestone 18th birthday, and while we ring in her monumental occasion, here is the story of Prince Edward and Sophie, Countess of Wessex's eldest child's incredible journey from birth to adulthood.
It's clear the Queen's youngest granddaughter is channelling the monarch's panache for colours and coats.
Louise has been known to test some fashion forward ensembles - her spring-time floral skirt worn in 2019 is case in point.
The visit to Bristol Zoo was a special day for the Wessex family, Sophie was accompanied by parents and little brother, James Viscount Severn, 13, as they were pictured in a rare photo opportunity together.
In March 2021, we caught another glimpse of Lady Louise at the funeral of her grandfather, the Queen's husband Prince Philip.
As to be expected, the young royal was respectful and sombre for the emotional occasion alongside her family.
Lady Louise was only eight-years-old when she made her global debut as one of the bridesmaids at Duchess Catherine of Cambridge's wedding to Prince William in 2011.
The youngster was joined by Margarita Armstrong-Jones, Grace Van Cutsem, Eliza Lopes, and pageboys Tom Pettifer and William-Lowther Pinkerton.
The only daughter of Prince Edward, Earl of Wessex, and Sophie, Countess of Wessex was born on 8 November 2003.
Sophie was rushed to hospital a month before her due date and at the time, Prince Edward was on a royal tour of Mauritius.
Lady Louise was born prematurely and there were some serious complications around her birth.
It was reported that a placental abruption caused severe blood loss to both Countess Sophie and Lady Louise forcing royal surgeon and gynaecologist Marcus Setchell to perform an emergency Caesarean section.
Speaking of the testing ordeal to the Sunday Times, mum Sophie admitted it was a "very scary" moment.
"For the first 10 years after [Louise] was born, I found it very hard to go to prem wards. It brought the whole thing back, but I've learnt to cope," she explained.
The royal parents officially announced their daughter's name on the 27th of November 2003, giving her the moniker Louise Alice Elizabeth Mary Mountbatten-Windsor.
When Sophie and Edward married in 1999, they decided they wanted their future children to lead a normal life - opting to drop "HRH" titles, which is why Louise has the title "Lady."
The granddaughter of Queen Elizabeth II and Prince Philip is currently 14th in line of succession for British throne.
In the same Times interview, Sophie elaborated on her hope for her children to leave relatively normal lives.
"We try to bring them up with the understanding that they are very likely to have to work for a living," she said.
As for schooling, Sophie said both Louise and James attend "regular school" and she hopes that her daughter will one day go to university.
"She's working hard and will do A-levels. I hope she goes to university," Sophie explained.
"I wouldn't force her, but if she wants to. She's quite clever, so I think probably, whereas James I don't know."
Although Louise was given the title 'Lady' by her parents so she could live a more normal life, with Prince Harry no longer in play for royal duties, rumours have swirled that the Queen's youngest granddaughter will take his place in rank.
However, according to Express UK, it's highly unlikely because a royal has never changed their titles once turning 18.
Royal source, Marlene Koenig, revealed that it would fall to Queen Elizabeth rather than Louise if such a decision were to be made.
The young royal was born with esotropia, a condition that turns the eyes outwards.
The illness saw her undergo her first surgery at just 18 months - unfortunately it was not successful.
Growing up, she faced issues with her vision, which lead to her parent's decision for her to have a second operation in 2014.
It has been reported that it was a success and now Lady Louise has better vision.
"It's still not perfect - but none of us are," Sophie told The Times.
Speaking of her daughter's condition, Countess Sophie shared, "Premature babies can often have squints because the eyes are the last thing in the baby package to really be finalised."
"Her squint was quite profound when she was tiny and it takes time to correct it. You've got to make sure one eye doesn't become more dominant than the other but she's fine now," she added.
Her daughter's ailment inspired the Countess of Wessex to become a patron of the International Agency for the Prevention of Blindness and a global ambassador for Vision 2020.
One of the most charming facts about the teen is the fact that she didn't realise she was royalty.
Her mother sat down for a chat with the BBC, recounting the hilarious moment her daughter figured out her grandmother and the Queen were the same person.
"Well, for Louise, actually, it was much more of a shock to the system," the proud parent recalled.
"It was only when she was coming home from school and saying, 'Mummy, people keep on telling me that grandma is the queen.' And I asked her, 'Yes, how does that make you feel?' And she said, 'I don't understand...' I don't think she had grasped that perhaps there was only one Queen."
Watch Countess Sophie recount the story below. Post continues after video...
The story resonated with Sophie and Edward's desire for their children to lead a normal life.
"They're going to have to go out and get a job and earn a living later on in life," Sophie reiterated previously.
"If they've had as normal a start in life they possibly can get, then hopefully that will stand them in good stead."
Lady Louise Windsor shares her grandparents' love of equestrian sport carriage driving - she even competed in the British Driving Society Championship for Young Driver.
Prince Philip was exceptionally proud of his granddaughter, given his passion for the sport, which he took up when he was 50.
Speaking in the BBC One documentary Prince Philip: The Royal Family Remembers Louise shared: "The Duke of Edinburgh has been so involved in my driving which has been lovely, but slightly scary because he invented the sport pretty much, but it's incredible to have learned first-hand from him and definitely made us closer, I think.
"After a competition, he would always ask how he went, his eyes would light up because he would get so excited when he talks about it."
After his passing, Lady Louise inherited her grandfather's driving ponies and carriage.