The document also reveals how after the Dotcom family arrived for a holiday in March 2010, the tycoon splurged $2.3 million buying eight luxury vehicles throughout his three-month stay - including two Mercedes on one day - before flying out again on a private jet.
"I make the ... property claims based on the legal advice of my marital property counsel in New Zealand and my understanding of the applicable property laws," Mrs Dotcom said in the court filing.
The legal claim by Mrs Dotcom came after the US authorities filed papers in the District Court of Eastern Virginia to seize $78 million held in Hong Kong and New Zealand since the raid. The sum is made up mainly of cash but includes millions of dollars worth of luxury cars seized in New Zealand.
The amount of money restrained falls well short of the overall amount the court papers show the US will attempt to recover - the $220 million revenue traced to Megaupload.
The US papers seek the forfeiture through the courts of all assets able to be traced to the seven people named in the original FBI indictment, which includes the four arrested in New Zealand in January 2012. Those men - Dotcom, Finn Batato, Bram van der Kolk and Mathias Ortmann - face a long-delayed extradition hearing early next year.
The assets listed were already seized at the time of the original raid but the US Government is now seeking the court's permission to take and sell the property, claiming the cash.
The court papers set out the purchasing pattern for luxury vehicles. Dotcom, who is a Mercedes enthusiast and car lover, arrived in New Zealand for his second visit on March 6, 2010.
By the time the family flew out again on June 30 that year, Dotcom had spent $2.3 million buying eight vehicles - even before gaining residency. The cars included six Mercedes and a Rolls-Royce.
Dotcom's lawyers have asked the courts to reject the bid, saying the original criminal case was already without warrant and the civil forfeiture case added an unfair burden.
Dotcom told the Herald he would make no comment on matters involving Mrs Dotcom.
The tycoon has shunned New Zealand media since the election, aside from occasional tweets. But he made one media appearance in an online New Yorker interview in which he blamed the FBI case for the end of his five-year marriage.
"My wife and I, we were happy before the case," he said. "We were living in this completely happy bubble in our happy world and we didn't have any issues."
Dotcom, who has four of his five children with Mrs Dotcom, told the New Yorker the raid and the pressure that followed made it difficult to live a normal life. "For me, that is the single biggest negative outcome of all of this - that I've lost my family. I will have my kids grow up with a broken family and I will not be with my wife who I loved, and that's very sad."
Mrs Dotcom's lawyer, Mark Sandelin, said she did not want to comment.
Professor Nicola Peart, an Otago University expert in family property law, said Mrs Dotcom would benefit from the principle of equal sharing of relationship property if the claim were made in New Zealand.
The US law of forfeiture might have no interest in marital claims, the professor said. However, Mrs Dotcom would have no right to claim without filing the papers. "It is certainly sensible to make a claim."
