NBC News — The richest woman in the world is Australian. Business magazine BRW says Gina Rinehart, 58, is worth $28.2 billion. Rinehart's wealth increased some $18.5 billion in the past year alone thanks to a mining boom in Australia.

She made her debut on the rich list after the death of her father, a mining tycoon, in 1992. Her net wealth at that time was estimated at $73 million.

She may not hold on to that fortune for long.

An only child, Rinehart is battling her three eldest children who want her removed as trustee of the family fortune.