Gina Rinehart, Australia's richest person and once the world's richest woman, may have lost last week the Rhodes Ridge iron ore mine to Wright Prospecting, but over the weekend she won a more important battle.

It's the one involving her three estranged adult children. Reports said that the number of her children who had opted to continue their protracted family feud in court has gone down to just two after the youngest estranged child, Hope Welker, waved the white flag to her mother.

Reports said the move was because of the second to the youngest daughter of the mining magnate being broke and losing hope of winning their battle against the family matriarch.

Ms Welker is believed to have been auctioning her clothes and other personal items to survive in New York where she lives with her husband, Ryan Welker, and two children.

She withdrew from the case because of financial problems as her savings, which had at one point dwindled to $60,000, was used for legal bills.

Her two siblings in the lawsuit, brother John Hancock and sister Bianca Rinehart, are reportedly sending money to Ms Welker since 2012 to pay for the children's school fees, rent and other daily expenses.

In an email to Ms Rinehart in September 2011, Ms Welker complained that she could not afford a cook, housekeeper or bodyguard because of her mother's move to block the release of their funds from the trust set up by their grandfather, which led to the lawsuit to remove their mother as head of the trust fund.

Ms Rinehart attempted to block the publication of these juicy details, but also lost in her bid to keep the family secrets hidden from public view.

Mr Welker is said to be searching for a job after he resigned as director of Mineral Resources, partly owned by Ms Rinehart's Hancock Prospecting, after the lawsuit was initiated by Ms Welker.

Her siblings are planning to continue the lawsuit despite the decision of Ms Welker to drop it and her plea for them to do likewise.

In May 2012, in a dramatic twist, Ms Rinehart agreed to allow the division of the family trust, in effect revoking the matriarch's moving the vesting date to 25 years later. The three children want to sell the shares but are prohibited from selling the shares to anyone outside the family.

Even if the children sell their shares to their mother, they would still need to pay millions of dollars in taxes which they do not have, thus the case would likely go on and has March 12 as the next hearing date.

For Ms Welker to withdraw from the lawsuit, she needs to have her two siblings agree to waive her share of the legal bills which had ballooned to more than $1 million.

On Ms Rinehart's side is her youngest daughter, Ginia, who drives around in a Rolls-Royce and is training in Rio Tinto as she prepares to assume a bigger role in Hancock Prospecting. Her three siblings are reportedly miffed at the privileges that their youngest sister is enjoying.

Ginia and Hope have the same father, Frank Rinehart, while John and Bianca are Ms Rinehart's children from her first marriage to Greg Hayward.

News of the surrender of Ms Welker overshadowed the recent loss of Ms Rinehart in another prolonged court battle with Wright Prospecting, which belong to the heirs of her father's former business partner.