RIO DE JANEIRO, Brazil (AFP) — Gaurika Singh may be the youngest competitor at the Olympic Games in Rio but the 13-year-old says there's nothing unusual about that in her London school.

The Nepalese swimmer will be the youngest competitor at the Games when she dives into the water for the 100m backstroke heats on Sunday.

But she said such achievements at Haberdashers' Aske's School for Girls in Hertfordshire, England – a highly competitive independent school – are par for the course.

When asked what her school friends think about her Rio jaunt, Singh told AFP: "They're happy for me but a lot of people at my school are successful!

"Like national tennis players, a girl playing in the Harry Potter film -- the new one -- and Matilda on Broadway.

"So, yeah, we all have different opportunities."

Singh, who was born in her native Nepal but moved to Britain when she was two -- first to Scotland, then Preston and Leeds before her family finally settled in London -- is not even sure she's the best athlete in her school.

"There's a Wimbledon player in the sixth form, doing junior Wimbledon."

Singh may be making waves in Brazil due to her age but she is taking it all in her stride.

"I don't really think about it much, I'm here competing like everyone else, so I don't see any difference."

However, she does admit that she never dreamed of becoming an Olympian when she first started swimming as a "hobby".

"I started swimming while I was really young but I didn't think it would take me this far," she admitted.

"I started swimming competitively when I was nine and I didn't really think I would be here, so it's amazing and unbelievable."

Singh trains at the Barnet Copthall club in London with two other Rio Olympians, Pakistanis Harris Bandy and Lianna Swan.

But her road to the Olympics began when her coach decided she should try out for the Nepalese team.

"My coach wondered if I could do the national swimming (championships) in Nepal so it first started then," said Singh.

- Goodwill ambassador -

That led to the most "terrifying" experience of her life, though, as Singh was in Kathmandu during the 2015 earthquake that devastated the country, leaving almost 9,000 people dead.

Singh, her mother Garima and younger brother Sauren cowered under a table in their fifth floor apartment as the earthquake struck before escaping by the stairs to flee aftershocks.

"Fortunately, it was a new building so it did not collapse like others around," she said.

But tragedy led to another opportunity for Singh who collaborates with a charitable organisation called Shanti Education Initiative.

"My dad's friend originally had a charity to build schools that the earthquake destroyed," said Singh.

"They made me a goodwill ambassador and I donated all the prize money I got (to it)."

In a country not known for its swimming prowess, Singh's stock and profile is set to blossom in her homeland.

It's a remarkable journey for a young girl who swam "for fun".

"It's one of those things you take up as a child and drop off later, but I liked it!" she said with a giggle.

Not dropping off later proved to be a wise choice for the precocious teenager with a classic English accent.

Although she'll still be hard-pushed to impress her school friends.