Lady Louise Windsor has been working an unlikely summer job. Photo / Getty Images

Queen Elizabeth's granddaughter Lady Louise Windsor has secured herself an unlikely job.

The 18-year -old royal has reportedly been working at a garden centre over the summer for little more than £6.83 ($13.80).

The Sun reported minimum wage for 18-year-olds in the UK is £6.83 an hour, and despite being 16th in line to the throne, the young royal has limited work experience it is unlikely she was paid much more than that.

It comes after the teen, who is the daughter of Prince Edward and his wife Sophie, Countess of Wessex - was revealed this week to be heading to St Andrew's University in Fife, Scotland to study English.

It's the same prestigious university the Duke and Duchess of Cambridge studied and met at.

However, while she was awaiting her A level results this week, Louise surprised shoppers working the normal job manning the tills for minimum wage.

One customer told The Sun: "I couldn't believe it was Lady Louise — I had to look twice.

"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 said: "The staff seemed to adore her. It's not every day you buy your begonias off a royal."

Louise - who chose not to become a working royal - is said to have studied English, history, politics and drama, but her A level grades have not been made public. However, The Sun reported that for the young royal to be successful in her application to St Andrew's University she would have to receive at least two As and two Bs.

They later reported she received the happy news of her acceptance into the university this week while with her family and the Queen, 96, at Balmoral in the Scottish Highlands.

The teen - who is believed to have inherited her grandfather's carriages following his death aged 99 last year - took part in the Duke of Edinburgh Award scheme when she was at school and admitted she was keen to do so in order to make Prince Philip "proud".

She said: "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. I definitely hope I have made him proud.

"I'd always wanted to do it because of the skills you develop as a result.

"My favourite part was my expeditions. Just having that level of independence and self-sufficiency and having that sense of achievement when it was finished."

- Additional reporting by NZ Herald