Three children of Australia\'s richest person, Gina Rinehart, were \"motivated entirely by greed\" in taking their mother to court for control of a family trust, their youngest sister said. Iron ore billionaire Rinehart, ranked 29th on Forbes\' global rich list with an estimated wealth of more than US$18 billion, has been embroiled for months in the legal dispute with three of her four children. On Friday, she lost a High Court bid to keep the proceedings out of the media, prompting her son John Langley Hancock, and her youngest daughter and ally in the case, Ginia Rinehart, to issue statements. \"This case is motivated entirely by greed and I have no doubt that one day soon my brother and sisters will regret putting money before family,\" Ginia commented. She said it was \"very painful\" that the dispute over control of a family trust had become so public, adding that Gina Rinehart was a \"loving and hard-working mother (who) has only ever wanted the best for children\". The row stems from a family trust set up by Gina Rinehart\'s father, the late Lang Hancock, in 1988 with the four grandchildren as the beneficiaries. Rinehart wanted the children to give her long-term control of the trust, but three - John Hancock and sisters Bianca Hope Rinehart and Hope Rinehart Welker - have refused and instead want their mother removed as trustee. In a statement issued by her lawyer, Gina Rinehart said she was \"extremely disappointed\" that three of her children had decided to make a private matter public, a move which she said would jeopardise the security of the family. \"The plaintiff children have seen fit not to follow sound advice from family friends that if they are not happy they should go out and earn for themselves,\" the statement said. The children had enjoyed a life of privilege and had been allowed to choose multi-million dollar homes with water views and swimming pools in addition to trust dividends and other benefits, it added. But John Hancock said he was already supporting his family by working, adding he would not be able to \"replicate my youngest sister Ginia in \'earning\' the achievement of a Rolls Royce at 25\". \"What does (my mother) want me to do - take up her offer of free money if we do as she says? No thanks!\" he said.