Millionaires & Billionaires

Billionaire's secret daughter gets $20 million

Looks like Olivia Mead will be able to afford her Mexican walking fish and jewelry-encrusted bass guitar—lots of them, in fact.

Mead, the "secret daughter" of the late Australian billionaire Michael Wright, became a minor Web sensation in early February after demanding more from her father's estate, worth $3.1 billion Australian dollars ($2.4 billion). She submitted to the court an exotic shopping list of her demands, including a AU$250,000 diamond-studded bass guitar and AU$2,014 a year to keep a Mexican walking fish.

In a surprising decision, the court Thursday awarded Mead AU$25 million (about $20 million)—more than twice the amount Mead was requesting from the court.

Read MoreWhy 1% are like one-hit wonders

"The starting point in reaching that conclusion is the size of the estate," Master Craig Sanderson said in his judgment. "The deceased had a vast fortune and he was in the fortunate position of being able to provide for all parties who had a claim on his bounty."

Supreme Court in Perth, Western Australia
Ian Trower | Getty Images

According to Australian press reports, Mead's mother Elizabeth broke down in court upon hearing the news. Neither spoke to the press.

$450K vacation? Billionaire divorce reveals big $$

Mead's lavish requests to the court overshadowed the legal issues. She demanded a AU$2.5 million house, which would be refurbished twice at a cost of AU$500,000. She demanded a AU$250,000 bass guitar made out of 10,000-year-old Siberian mammoth ivory, 24-carat gold inlay and knobs topped with 3.3 carat diamonds. She also wanted a AU$1.2 million crystal-encrusted piano.

$1 million a month to raise the kids?
VIDEO1:1901:19
$1 million a month to raise the kids?

She also wanted payment for all of her expenses for the next 77 years. Those include five pairs of AU$5,000 shoes a year, 20 pairs of AU$300 shoes a year, AU$40,000 a year for holidays, two cars, AU$10,000 a year for handbags and fashion accessories.

Read MoreThe rich dogs of Instagram

Australian press reports say the judge described some of her requests as "fanciful," including the guitar. But the decision was not based on fairness or spending needs, but on the size of the estate.

"Even in this day and age, $25 million is a considerable amount of money," Master Sanderson said. "But in the context of this estate, it is little more than a rounding error."