Elisabeth Murdoch said today she had no ambition to succeed her father Rupert as head of his News Corp global media empire.
But she said she had intervened to limit her brother's ambitions.
"I really harbour absolutely no ambition for a top job as head of News Corp," she told a question and answer session at the annual Edinburgh Television Festival.
She was speaking the day after she used a keynote speech to attack James, previously seen as the most likely Murdoch to take over as head of News Corp, and to praise the values of her father.
That speech had been interpreted by some as her pitch for the top job, portraying herself as having the purpose to lead the company after it lost its way in the wake of the phone-hacking scandal at the now-defunct News of the World newspaper.
Elisabeth left the family business to her younger siblings James and Lachlan more than a decade ago.
She said she had urged her brother James to step back and had said Rebekah Brooks, her father's favourite executive, should resign in the wake of the phone hacking crisis that engulfed the company last summer.
Elisabeth also said she had no plans to join the board "at the moment", but would continue to make a contribution as a shareholder.
"I think and hope the family will be positive contributors even as shareholders in terms of the long-term interest of the company and the other shareholders, but that's really as far as I see it," she said.
Elisabeth was going to take a position on the News Corp board after the company bought her production company Shine, but did not do so as the crisis raised questions about the family's management of the group.
In the wake of the phone-hacking scandal, James Murdoch resigned as chairman of News Group Newspapers and then as executive chairman of News Corp's newspaper arm.