Outside her native Australia, Gina Rinehart's name is likely to be met with quizzical looks – but all that could be about to change, because the 57-year-old from Western Australia is on track to become the world's richest woman.

Rinehart is a mining magnate who has built her fortune in the iron-ore-rich hills of the country's Pilbara region – an area the size of Spain, around 700 miles north of Perth. Forbes has just estimated her personal worth at $US18bn (£11.3bn) – putting her ahead of Google's founders, and fast advancing on the $26bn family fortune controlled by Christy Walton, of the US Wal-Mart dynasty.

Rinehart is known as a workaholic and for her strong political views, but has always been publicity-shy. However, a new, high-profile business deal, and a public row with her family, mean the multibillionaire's days of privacy are numbered.

Last week her company, Hancock Prospecting, launched a raid on one of Australia's oldest newspaper groups, Fairfax Media, which owns the Sydney Morning Herald and the Age in Melbourne, together with the Australian Financial Review and a string of radio stations. The swoop made Rinehart the largest single shareholder with a stake of just under 13%.

"I think her move into Fairfax is a power play," says Adele Ferguson, a senior financial journalist for Fairfax whose unauthorised biography of Rinehart is due for publication this year. "She's probably hoping to get some editorial influence, even if it's a perception thing. Journalists might think twice about what they are writing about her if she is the company's biggest shareholder."

Rinehart's assault on Fairfax followed her acquisition of a 10% stake (and a seat on the board) in the commercial television network, Ten.

"She wants to influence debate," says the Perth-based business writer Tim Treadgold, who follows the mining industry. "She wants to force Australian governments to pay greater heed to the resources sector because she genuinely believes that the future of this country is as a supplier of raw materials to China, not as a manufacturer in competition with China," said Treadgold.

Some of Rinehart's views may be controversial, but she is a woman Australians are increasingly taking notice of.

She is a climate change sceptic (last year she helped fund the controversial visit to Australia of the climate change denier Lord Monckton) and has previously promoted the idea that Western Australia secede from the rest of the country. She once looked into the feasibility of using a nuclear bomb to create a harbour on the north-west coat of Australia.

Rinehart is against the government's proposed new tax on mining profits and in favour of bringing in cheap "guest labour" from Asia for the mining sector.

Treadgold calculates that Rinehart's Pilbara mine, Hope Downs (which she owns in equal partnership with Rio Tinto), is likely to deliver her a profit of close to $A3bn (£2bn) a year when it reaches full production of 45m tonnes a year.

When combined with Rinehart's other mines due to come on line in the next few years, Treadgold believes she could be on her way to being the richest person in the world. A Citigroup Global Markets paper last year on the next generation of mines around the world estimated that three of the top ten were owned by Rinehart's Hancock Prospecting. "What hit me was that she was named [in the report] alongside the usual corporate suspects like BHP, Anglo American and Xstrata but what you have to realise is that she owns these mines personally," he said.

The scale and speed at which Rinehart has accumulated her wealth is nothing short of breath-taking. Born Georgina Hancock, in 1954, she is the daughter of the legendary Western Australian mining figure Lang Hancock – the so-called "King of the Pilbara". Lang is credited with discovering vast tracts of iron ore deposits in the region in 1952 where his family had been pastoralists for generations.

He was regarded in equal measure as a visionary and ruthless opportunist. He did business with the Romanian dictator Nicolae Ceausescu and reportedly suggested "no-good half-caste" Aborigines be sterilised so they would "breed themselves out in the future".

Lang died in 1992, leaving the family business to his only child, Gina, then a 38-year-old widow with four children. It was in serious trouble, bar a 2.5% royalty stream from iron ore sales on mining leases belonging to Rio Tinto in the Pilbara (a deal done by her father in the 1960s). In today's terms it's estimated that the royalty brings Rinehart an annual revenue of about $US107m a year.

But since Lang's death, Rinehart has built Hancock Prospecting into an important player in the Australian resources boom. As well as 50% of the massive Hope Downs mine, she owns another huge mine in the Pilbara, Roy Hill, which is expected to begin exporting in 2014. She also has other investments in exploration for uranium, lead, gold, diamonds and petroleum.

The power of the mining and resources industry is reshaping the Australian economy. As the world's largest exporter of iron ore and coal (much of it bound for China and Japan), rising commodity prices have brought increased profits which in turn have buoyed the economy.

Australia was one of the few developed countries to escape recession during the global financial crisis – because mining filled the national coffers and kept the economy strong.

Rinehart sees the resources sector as the future of the Australian economy and her views on the Labor government's plans to increase taxes on mining profits are well known. In 2010, she donned some expensive-looking pearls and shouted "Axe the tax" from the back of a flat-bed truck in Perth.

A former West Australian attorney general , Jim McGinty, told the Age newspaper that the image of her splashed across media outlets left an indelible impression. "All I could think of was Gordon Gekko shouting 'greed is good'," he said. "Gina was basically saying 'I don't want to pay my fair share of tax.'"

She got her message across. Two weeks later, the then prime minister and chief proponent of the tax, Kevin Rudd, was dumped by his party. A much watered-down version of the tax is due to pass the senate early this year.

Rinehart has always guarded her privacy carefully. She is rarely seen out and about in Perth and refuses almost all interview requests. So do her friends. Others fear they will be sued if they speak against her.

But her recent foray into media ownership has cast a spotlight on her – and on a bitter family feud with three of her four children that would not be out of place in a Hollywood script.

Rinehart's three oldest children are trying to have her removed as the head of a family trust set up by Lang Hancock. The trust owns almost a quarter of Hancock Prospecting.

She has sought orders in two courts (including the high court) to have details of the dispute suppressed. But last Friday some details spilled out in court, including a security report commissioned by Rinehart that argued her four children and five grandchildren faced heightened security risks, including kidnapping, murder and terrorism as a result of the publicity surrounding the dispute over the family trust.

Rinehart's eldest child, John, launched a blistering attack on his mother the next day. "I can support my wife and children in a modest manner from the work I do but I can't provide the level of funds required to deal with security issues – real or imagined – associated with begin the son of a woman worth more than $A20bn," he said in a statement.

"When my mother buys a few hundred million dollars worth of Fairfax, it's going to draw some attention," he continued. "But she won't share a penny to help protect he grandchildren from the risks she – the trustee of our family trust – is creating by her own actions. What more can I do than communicate to any kidnappers out there – over my dead body and you will be wasting your time anyway. If you think you are going to get anything from my mother, good luck."

Emails revealed in court showed her other children had requested money for bodyguards, chefs and housekeepers.

"I don't think you understand what it means now that the whole world thinks you're going to be wealthier than Bill Gates – It means we all need bodyguards and very safe homes!!" wrote Hope Rinehart.

However the dispute with her children is settled, Rinehart's colossal wealth means she will continue to make and indelible mark on Australian life – both economically and, with her recent acquisition, through the media too.