Millie Bobby Brown, pictured, 12, is making a quite a name for herself on Netflix show Stranger Things

It has become the word-of-mouth hit of the summer. Netflix’s supernatural TV drama Stranger Things is so addictive, even Hollywood giant Steven Spielberg has hailed it as the best show of the year.

Even more remarkable is the extraordinary sacrifice made by the family of the 12-year-old British newcomer who has outshone Hollywood star Winona Ryder to become the sensation of the series.

Schoolgirl Millie Bobby Brown has, according to the industry bible Variety, ‘the kind of presence some actors take a lifetime to acquire. She is about to be cast in a lot of projects’.

Some fans are so besotted with her character ‘Eleven’ they are having her name tattooed on their arms.

Others are dressing as her character – an orphan with telekinetic superpowers – to watch the series at Stranger Things pyjama parties.

But, even aged just 12, hers is far from an overnight success story.

In her first ever interview, Millie reveals the remarkable faith her family have shown in her talent, which has seen them pushed to the brink of bankruptcy.

‘It was very hard,’ she says. ‘There were lots of tears along the way.’

Millie’s parents sold everything to move to Hollywood to help the youngster fulfil her dreams.

She quickly gained bit parts in NCIS, Modern Family and Grey’s Anatomy, but while she made the shortlist for ‘huge’ projects including Spielberg’s recent film The BFG, she kept missing out on the starring roles.

Things were so tight, Millie’s British-born manager Melanie Greene lent the family money to help them survive.

‘My older sister left. She didn’t want to do it [America] any more,’ Millie says. ‘It was tears, tears, tears. We went through tough times.’

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Millie, second left, pictured with her family (from left brother Charley, father Robert, mother Kelly holding baby sister Ava and sister Paige) revealed her family 'went broke' supporting her acting dream

But she finally got her break as the enigmatic 'Eleven' in Stranger Things, pictured

Last summer, the family admitted defeat when their money ran out.

They moved back to the UK so broke they had to stay with an aunt. ‘I was devastated. I wasn’t getting work. I thought I was done,’ says Millie.

Back in England, she hit her lowest ebb after an unpleasant experience with a casting agent: ‘She said I was too mature and grown up. She made me cry.’ Later that day, she auditioned for Stranger Things.

‘I had to cry in the audition. My emotions were so raw, I hit it out of the park.’

Within weeks, the family were on a plane back to the US, where Millie filmed in Atlanta late last year. The show has transformed her life.

‘It’s crazy,’ Millie says sitting in a five-star hotel in Los Angeles where she is being ‘bombarded’ with film and TV offers.

‘I never in my wildest dreams thought this would happen.’

Stranger Things is a dark story which centres on the disappearance of a small boy who vanishes into thin air.

Millie, left, said she grew close to co-star Winona Ryder, right, who was 'protective' of her

Her character in the show, right, has special abilities after being the test subject for a Government experiment

Millie, centre with some of her fellow cast members, has grown up in Spain, Bournemouth, Florida

It features secret Government experiments, mysterious forces from another dimension and a strange girl – Millie’s character – with telekinetic powers.

In person, Millie is funny, confident, but undoubtedly still a child. Her legs are covered with bruises from a recent trip to a water park.

She is third of four children born to Robert, an estate agent and wife Kelly.

Her older sister Paige, 23, works for the Nationwide building society and she has a brother Charlie, 18, and younger sister Ava, four.

Kelly found out she was pregnant with Millie in 2003, just before the family relocated to Spain, where Robert’s parents ran a restaurant.

From the start, Millie – born in Marbella in 2004 – was different.

Her father recalls: ‘My other children would watch cartoons, but Mill watched musicals – Chicago, Moulin Rouge, Annie and Bugsy Malone. She’d belt out a tune. She was performing from day one.’

When Millie was four, the family moved back to the UK. She attended Pokesdown Community Primary School in Bournemouth.

‘I did a lot of school plays. I was a drama queen,’ she says.

At eight, her family moved again, this time to Florida to launch a tooth-whitening business.

Millie says: ‘I was annoying my father one Saturday and he said: “We need to find you something fun to do.”’

Millie, left and right, revealed she got into acting properly in Florida when her father suggested she find 'something fun to do'

So she was enrolled in a weekend stage school: ‘It was acting, dancing, singing four hours every Saturday. There was a showcase and an agent said she wanted to represent me.’

When the agent said they needed to move to Hollywood, the family headed west in an extraordinary act of faith.

Robert had a friend who engineered an introduction to Greene who immediately spotted her talent. ‘She’s a natural,’ she says.

On the set of Stranger Things, co-star Winona Ryder was a friend and mentor. Millie points to a pretty ring on her middle finger: ‘Winona gave me this. It’s an Irish wedding band for loyalty, love and friendship. She was protective.

‘We’d eat cheese and crackers in her trailer because she’s like a mouse, she’s always eating cheese. We’re very close.’

Millie has been inundated with offers of work and a second series of Stranger Things seems likely, but – even after all the family sacrifices – her father says he’s determined to keep her feet on the ground.