So, how did the money end up in her bank?
It all started with a typo her bank made in September.
The National Australia Bank (NAB) sent 26-year-old Ms Wainwright a letter accidently typing that the mortgage repayments for her home loan would be $25,102,107 instead of the agreed-upon $2,500.
A linked account at another bank obliged and transferred the astounding amount of $25 million, giving Ms Wainwright the shock of her life when she saw her bank balance plunge deep into the negative.
When she flagged the problem, NAB refunded the amount... and then some.
"I'm a lawyer, which is why I haven't spent the money," she told Fairfax Media. "Mostly because I figured it wouldn't play out that well trying to play dumb on that."
That didn't stop her from joking about it on Facebook, however, where she posted a screenshot showing $24.5 million in her account:
In a statement reported by The Daily Telegraph, the bank says the "error" has since been fixed and claims Ms Wainwright would not have been able to withdraw the millions - even if she wanted.
"Although the funds appeared in the account, they were not available for withdrawal," the bank said. "We thank the customer for contacting us and we're sorry for any trouble caused." Click for more trending news