When Lhakpa Sherpa was a small child growing up in a tiny village in the Himalayas, her mother warned her that if she didn’t behave herself, the yetis would come and snatch her away.

It was a hollow threat – or so she thought. Then, one day as she played outside with her friends, she saw them: very tall, with blond hair and blue eyes, climbing up the hill in her direction. The children screamed in panic and scattered. When Sherpa’s mother heard the commotion and saw the figures reaching the village, she too screamed and ran from the yetis. It was her community’s first encounter with western tourists.

She tells this story to illustrate how far she has come: from Makalu – a verdant, temperate and sparsely populated Nepalese region on the doorstep of Mount Everest – to the slightly less atmospheric northern English city of Sheffield, where we meet during DocFest to talk about the documentary Mountain Queen: The Summits of Lhakpa Sherpa.

It is a film that details the extraordinary life of a 48-year-old single mother working in a supermarket in the US state of Connecticut, who also happens to be one of the best mountain climbers in the world.

“Look like Makalu,” she says generously, gazing out of the bus window at the wet green hills, as we wind our way up into the Peak District, the location for our interview. We’ve chosen this spot because, as the first Nepalese woman to summit Everest and survive – one of a dozen world records she holds – Sherpa feels more comfortable walking while we talk.

Whip-smart, she speaks a poetic and colourful personal English dialect that her friends call “Lhakpa-ese”. English is one of seven languages she speaks and she understands many others, learned while working as a guide to westerners on Everest.

“People say, ‘Why you going Everest? ‘Why you wanna go K2?’ My heart want. My heart does not have any other job,” she says, maintaining a steady pace in the frigid Derbyshire weather as we hike up to Bamford Edge. A steady pace is the secret to scaling mountains, she says – and she would know, having summited Everest 10 times and recently conquering the world’s second highest peak, K2.

“That is my sport. I want to see this beautiful mountain changing in the dynamic looks.”

Though her name might suggest otherwise, she is the first in her family to climb. Her parents were yak farmers and she grew up during a time when girls in Nepal were not educated. Sherpa would carry her younger brother two hours each way to school but was not allowed to go inside. She still cannot read or write.

Though she was expected to become a housewife, Sherpa wanted to be out in the mountains. “I’m a little bit looks like a tomboy type,” she says.

As European tourists began to return each year, she watched young men from the village get work as porters, carrying supplies and equipment through the Himalayas. Though she was stronger than some of the boys, they wouldn’t hire a girl. But instead of giving up, she cut her hair short, donned a hat and secured her first job, carrying loads as heavy as 100kg.

“My secret life. I love it,” she says. She worked her way up from “kitchen boy” to becoming a guide, using the encyclopaedic knowledge she gained. She knows the Everest trails without a map, understands the weather and how quickly it can change – the kind of experience that can be life saving.

Despite a spate of deaths of Sherpas working for western climbers in recent years, she doesn’t feel the work in itself is exploitative. But she laments how being a guide can seem like a good career path to young people in her village, who don’t have other options.

“In Makalu, young Sherpas, they not educated, they always coming, they wanna go Everest with no training,” she says.

As well as a fee for the trip, it is customary for Sherpas to be paid a summit bonus, of between $4,000 and $10,000, for getting a client to the top, she explains. It means “they work so hard”.

“This year, a young Sherpa die, it take me my heart down,” she says. “Young Sherpa need more training. A Sherpa life is very, very difficult.”

In the film, we meet Sherpa as she climbs a steep, icy rockface to Everest Camp Four – the start of the death zone, so called because the altitude makes it impossible to breathe for long periods without supplies of oxygen – where she camps in below-freezing temperatures, a fierce wind raging against the sides of the tent.

Her 15-year-old daughter, Shiny, waits anxiously at Base Camp, as the adults attempt to contact Camp Four on a two-way radio.

“How many tanks of oxygen does each person have?” she asks. She is not reassured by the reply, and neither are we.

The film made its debut to standing ovations at the Toronto film festival and was picked up by Netflix to be released globally later this year. With the right momentum behind it, it seems ripe for the Oscar nominations list.

Six years in the making, involving technical and at times perilous shooting conditions, it is a feat by British director and two-time Oscar nominee Lucy Walker.

More remarkable than Sherpa’s physical achievements, though, is the depth the film goes to in revealing her personal life: first, a relationship with a philanderer who looked down on her and left her with a baby son, causing shame so immense she felt unable to return to her village.

In particular focus is her relationship with her daughters’ father, Gheorghe Dijmărescu, a fellow mountain climber, who became controlling, cheating and violent. When he hospitalised her in 2012, a social worker helped move Sherpa and the girls to a women’s refuge, leaving behind all their possessions. Dijmărescu died from cancer in 2020.

“You know, I not have good men come my way. All the time bad men come my way,” she says. “Maybe they see me tough, I don’t know.”

Her mindset has got her through a lot. “Whatever happen bad things, I stay positive,” she says. “People say why you so strong mentally, physically? Because I work so hard.”

The film hasn’t changed anything tangible for Sherpa yet – she cleans houses in Connecticut to make ends meet and crowdfunded her last Everest summit, as sponsors are not easy to come by. Companies that might be expected to fiercely compete to be associated with her, such as the US outdoor brands Patagonia, North Face and Mountain Hardwear, all turned her down. As did her former employer, Whole Foods.

“I tried so many that ignored the letters. I don’t know why they ignore, I’m a great climber,” she says, as if being the holder of the world record for the most Everest summits by a woman needed further explanation.

“I can show I’m an old lady, many people can do it,” she says.

“Many people want not give up. You look at this never educated Lhakpa but she not give up. She take her children, she take her mountain, she work hard in washing dishes and cleaning house, she not give up. But now my documentary, people see what I’ve been through and [in spite of that] I’m very happy.

“I’m chasing my dream because I want my children to go college and changing a little bit better life. I try my best, you know?”

After Sheffield, Sherpa is heading for London, Copenhagen and then Berlin, promoting Mountain Queen. “This two, three months, I look like queen. I’m not really queen – but I take it,” she smiles, as we descend the hill.

• Mountain Queen is released in cinemas on 26 July; on Netflix from 31 July

• This article was amended on 21 June 2024. Lhakpa Sherpa was the first Nepalese woman to climb Everest, but not the first woman, as an earlier version said. And Bamford Edge is not in “Yorkshire”, but Derbyshire.