The Court of Appeal has ruled there is currently no evidence which implicates her in the murder, despite the Crown's original claim that she ordered a hit on Fuller-Sandys after a burglary in the late 1980s.
She spent 15 years in jail for the crime, and until Wednesday, remained on life parole.
The court has also acquitted Mark Henriksen, and Gail Maney's brother, Colin Maney, who were convicted of the lesser charge of accessory to murder.
Stephen Stone, who remains in jail for the killing, as well as the subsequent murder and rape of Leah Stephens, who was said to have witnessed it, has been granted a retrial.
Maney said it had been an emotional morning. She was with her legal team when she got the news, in the form of a written judgement sent by email.
She scrolled right to the part with the decision, she said.
"There was a huge sense of relief, but a lot of mixed emotions."
The acquittal meant she no longer lived in fear of being recalled to prison for breaching parole restrictions, and no more regular questioning from probation officers about every aspect of her life.
"It feels great," she said.
"Such a sense of relief, because that was always hanging over my head."
A mother to five kids, and now a grandmother, she said the rest of her life now stretched on with possibility. She was not angry or bitter, grounded by her work in a Waikato cafe and supported by her community.
"I've lived with this for so long, now I've got to learn what my life's going to look like without this hanging over me."
She said while it had never been about the money - rather, about proving her innocence - her legal team would likely be pursuing compensation.
The reasons for acquittal
In their judgement, Justices Rebecca Ellis, Christine French and David Collins said the court had a number of reasons for deciding not to order a retrial for Maney.
There was an absence of credible evidence against her, along with the fact that it was "not appropriate to leave matters unresolved", and that she "has already faced two trials, has served her sentence, and remains at risk of recall to prison if she breaches the terms of her parole".
Any retrial would be long and complex, they noted, and a lot of time had passed since the disappearance of Fuller-Sandys.
"In our assessment, the principles of finality and the interests of justice require the case against Ms Maney to be brought to a conclusion," they wrote.
However, the case for Stone was different, and the seriousness of the charges against him warranted granting the opportunity for a retrial.
"Ordering a retrial does not of course require the Crown solicitor to commence a retrial. It is however consistent with the constitutional role of the Crown solicitor for her to make the final decision on whether or not to try Mr Stone again."
They noted that this case "now joins the list of instances where a miscarriage of justice has been caused by the failure of the police to disclose relevant material".
That was a letter sent by the lead detective Mark Franklin to the lawyer of one of the witnesses, which included a copy of a transcript of an interview with another witness, and a witness protection file which showed previously undisclosed meetings between Franklin and the witness.
These failures were "particularly egregious because those documents undermined Detective Franklin's assurances in the 1999 trial that the eyewitnesses evolving statements were not shared with one another," they wrote.
