She "ought to have known" an "excessive" sum was being "misappropriated for the benefit of her and her family" and was thus unavailable for the benefit of the rest home and its residents.
She also ought to have known that cheques from the rest home's account were being used to pay for apparently personal family matters such as college and primary school payments, rates and for cash.
Napier told the tribunal of the clear demarcation of roles between herself and her husband Duncan, who had held senior office roles at the rest home until 2012.
The couple had also been shareholders in the rest home's parent company.
She told the tribunal she did not take "an active interest either in the underlying commercial situation with the Torbay Rest Home and, subject only to their being adequate funds in her personal bank account to meet her individual outgoings, she was satisfied to let her husband handle the family's finances …"
An office administrator told the tribunal that while Napier was nurse-manager, staff pay rises were limited to the occasional increase.
The administrator said Napier had told her she would "dearly love" to give her a rise, "but there was just no money and the other shareholders had not approved it".
The administrator said the rest home's appearance had dropped drastically and another shareholder, Michael Single, said the place had "fallen into disrepair".
But Sara Napier said there was evidence the residents received a high standard of care, a programme of constant maintenance was in place and the laundry, lounge, gardens and kitchen had been upgraded.
The tribunal concluded, however, that there was "... inadequate expenditure on necessary items at the rest home during the period in question".
"Mrs Napier was negligent in her management and understanding of rest home finances, budgetary requirements, and expenditure needs.
This amounted to malpractice and brought discredit to nursing.
A charge that she abandoned her employment was established, but did not, on its own, warrant disciplinary sanction.
The two remaining charges laid by a Nursing Council professional conduct committee were not made out.
Napier has been censured, ordered to pay $31,000 towards the costs of her prosecution, and subjected to a year's supervision and other conditions from when she resumes nursing.
The tribunal case comes after civil court action brought by the rest home. In 2016, the Court of Appeal dismissed an appeal by the Napiers against an earlier High Court decision.
In a case brought by the rest home, the High Court had entered judgement in the home's favour for varying amounts against the Napiers and the Napier Family Trust. In total this came to around $2.235m, but the net amount recoverable by the rest home was about $1.438m.
The tribunal said of the High Court judgement: "Apparently that judgment has been satisfied, although the Tribunal was not given detail as to how this occurred."
