A 90-year-old Florida woman who became the largest sole lottery winner in US history six years ago is now suing her son and his financial adviser, claiming they poorly managed her $278 million in winnings, according to a new report.

Gloria MacKenzie took home the lump sum after taxes on a $590 million Powerball ticket she bought in mid-2013 at a supermarket in Zephyrhills, the Florida-Times Union reported.

Her son and caretaker Scott MacKenzie took control of managing the money. But five years later, things turned sour when the elderly woman sued her son and his investment manager for allegedly living off her winnings and poorly investing the proceeds, according to the 40-page lawsuit obtained by the paper.

The suit, filed by lawyer Gregory Anderson, claims Gloria MacKenzie missed out on “tens of millions of dollars” because the money manager her son hired was unqualified.

The investments earned nothing while the adviser overcharged and Scott MacKenzie never monitored what was going on, Anderson told the paper.

“You don’t have to know anything more than a branch manager at a bank to come back with some significant returns,” the attorney said. “At the same time, he [the investment manager] was charging my lady, age 90 and in ill health, $2 million in fees.”

Scott MacKenzie and his adviser are accused of breaching fiduciary duty, negligence and exploiting a vulnerable adult, among other allegations.

An initial version of the lawsuit was dismissed on Feb. 14, and the amended suit was introduced on March 6.

Then on Tuesday, Jacksonville Judge Virginia Norton heard a 20-page motion to dismiss the amended version but has not yet ruled on it.

It argues that Gloria MacKenzie can’t just sue because she’s unhappy that she didn’t get returns on her investments.

“That Gloria’s accounts did not increase in value as much as plaintiffs, in hindsight, would like is not a proper basis for a lawsuit,” the motion says. ”… Rather than pleading ultimate facts to support their claims, plaintiffs continue to pursue legal theories that are unsupported by the facts they allege.”

While Scott MacKenzie is “deeply disappointed” by his relatives’ decision to file the lawsuit, he believes the court will eventually see his side, one of his attorneys said in a statement.

“Although he strongly disagrees with the allegations that have been made, he will respect his family’s privacy by reserving any further comments until the case has been concluded,” Lee Wedekind III said.

It’s unclear how much money Gloria MacKenzie has left from the big win.