As the 17th in line to the throne, you might expect Lady Louise Windsor to at least insist on a seat in first class for a two-hour intercity rail trip.

Not so. The humble daughter of the Duke and Duchess of Edinburgh made do by sitting on the floor of a packed Great Western Railways service from London to Bristol as our exclusive picture shows.

St Andrews University student Lady Louise, 22, sat cross-legged on the 10.30am train, sipping a cup of PG Tips while working on an essay.

Sources say she seemed untroubled by the fact she could not bag a seat at Paddington and was ‘very polite’ to fellow passengers.

But then, the unassuming royal is used to uncomfortable journeys, given that her favourite pastime is carriage driving.

Her love of this dangerous, and unorthodox, equestrian sport was something she bonded over with her grandfather, Prince Philip.

She is not the first royal to travel unnoticed – her aunt, Princess Anne, boarded the London Underground in 2020, en route to a London Fashion Week event near St Paul’s Cathedral.

Lady Louise is said to be dating a dashing young Army man – and fellow St Andrews student – called Felix da Silva-Clamp.

Pictured: Lady Louise Windsor sat cross-legged on the 10.30am train, sipping a cup of PG Tips while working on an essay

He attended several of Lady Louise’s carriage-driving events in the summer, and the couple were pictured together at a St Andrews Day military parade last month.

Both looked smart in their military uniforms as they took part in the St Andrews Regiments’ Day Parade over Remembrance Day Weekend.

Praised for her dedication to duty at such a young age, the daughter of the Duke and Duchess of Edinburgh was among the members of the Officers’ Training Corps at the commemorative event for fallen soldiers on November 9 – just one day after her birthday.

Felix and Louise sported matching solemn expressions as they marched alongside fellow cadets in camouflage ensembles, all wearing red poppies, walking from Holy Trinity Church to the War Memorial in town, where wreaths were laid down.

Louise is currently in the fourth and final year of her English degree at St Andrew’s University, where she first met Felix. Their close bond has became the source of vast speculation since.

She has oft been hailed as the royal family‘s ‘secret weapon’, thanks to her natural poise combined with a down-to-earth nature and resemblance to her grandmother.

And the young royal seems to be making the most of her studies. In pictures released in March earlier this year, Louise was seen masterfully taking to the stage alongside her university friends as they all starred in a play.

She is known to have taken lead roles alongside Felix, who also shares her passion for theatre. She was also seen cosying up to Felix at her 21st birthday last November.

The duo wrapped their arms around each other, gently placing their heads together as Lady Louise took selfies on her phone, while in another image, she was seen snuggling up to Felix, placing her hand on his chest and her head on his shoulder.

The pair have been forging a strong bond over the past two years, with Felix – whose father is a solicitor – even reportedly travelling down to the Sandringham estate in Norfolk to see Louise at her driving competition in June, where she won an impressive silver medal.

In 2022, Louise spent the summer working at a garden centre before embarking on her higher education.

Louise was said to have been helping out on the tills, greeting customers, and pruning and potting plants – for £6.63 per hour.

One customer said: ‘She is a really modest and sweet young woman who is polite and attentive to customers. She seemed to be loving the job. You’d never imagine the Queen’s granddaughter would take on a role working behind a till.’

Another added: ‘The staff seemed to adore her. It’s not every day you buy your begonias off a royal.’

Thus far, Lady Louise has ensured her studies come first as she completes her degree – missing out on two Easter Sunday services in a row as she stayed in Edinburgh.

Despite being cousins with Princess Beatrice, Princess Eugenie, Prince William and Prince Harry, Louise uses the title ‘Lady’ rather than ‘Princess’.

She was not made a princess at birth because her father, Prince Edward, wanted to shield her from the pressures of a life in the public eye.

Speaking to The Sunday Times in 2020, her mother, Sophie, explained: ‘We try to bring them up with the understanding that they are very likely to have to work for a living. Hence we made the decision not to use HRH titles.’

Louise has previously expressed an interest in pursuing a career in ‘the military, diplomacy or law’.

A source told The Sun in August: ‘She talks about being very keen on a career in the military, serving the King and country. She is all about the Army Cadets and has fallen in love with it.’

If Lady Louise goes down the military path, she will be the first female royal since her late grandmother, Queen Elizabeth II, to do so.

She is thought to have been extremely close with her late grandmother, having paid nearly fortnightly visits to Elizabeth and Phillip.

Royal expert Ingrid Seward has previously explained that Louise and her brother, James, Earl of Wessex, ‘were the grandchildren that they saw the most’.

In comparison, ‘while the older ones were seen less frequently, this little girl was there every weekend’.

It was even reported that Louise had no idea her grandmother was the Queen until later in life, her parents wanting to preserve a ‘normal childhood’ for her.

Her mother, Sophie, once revealed in at an interview that as a child, Louise had come home one day saying: ‘Mummy, people keep on telling me that grandma is the Queen.’

Lady Louise was their seventh grandchild. And for Philip, she brought not just joy but a sense of personal pride.

This was because she became the first royal to officially carry the surname Mountbatten-Windsor – so allowing Philip’s surname, Mountbatten, to continue into the future of the Royal family.