Jacqui Bradley has been found guilty of fleecing around $15 million from 28 investors.
The former financial advisor was found guilty and convicted of 75 Crimes Act charges this afternoon, including those for theft by a person in a special relationship and dishonestly using a document.
The jury's verdict was unanimous and it took around four hours to reach it.
Prosecutors said Bradley's company, B'On Financial Services, was a "money merry-go-round", and funds were not being invested legitimately like clients believed.
"It was all a lie," Crown lawyer Kristy McDonald QC told the jury in the Auckland District Court yesterday.
Investor money was also used to pay other clients back, in what is commonly known as a Ponzi-scheme, and was spent by the Bradleys for schools fees, the mortgage on their Remuera home, clothes shopping and payments on a BMW, the Crown said.
While Jacqui Bradley originally faced charges with her husband, Mike Bradley died last year aged 63.
Bradley was remanded in custody until Friday, October 19 for sentencing.