Her offending began after working at the school for six months, and stretched over an eight-month period before suspicions were raised.
She then resigned in September and an internal investigation began.
Most of the offending involved falsifying invoices for a construction company that had been doing renovations at the school.
She also falsified a flight in the name of the school's principal and her partner to receive $1472.
However, that was eventually picked up by the principal when she said she hadn't flown to the destination.
A board member of the school described the incident as "sad", but the board had been heartened by the fact that all the money had since been paid back.
"In September we became aware of some financial irregularities and handed the matter over to police. The one thing that we're grateful for is the school has received all of the money back."
The charges she admitted were: using a forged tax invoice to obtain a pecuniary advantage, using two forged tax invoices, using six forged tax invoices belonging to a construction company between May and August, 2015, using a school cheque on March 31, 2015 worth $7500 with intent to obtain a pecuniary advantage, using a receipt for $1472 to obtain a pecuniary advantage, using a forged invoice with intent to cause the school a loss, and knowing the minutes of the Proprietor's Board meeting held on November 26, 2014 to have been altered by changing a resolution with intent to obtain by deception a pecuniary advantage caused the school to act upon the said documents.
In total she allegedly stole $796,000. Community magistrate Ngaire Mascelle entered intimated guilty pleas to all charges.
The woman will reappear in January when name suppression will again be discussed and pleas formally entered by a judge.
The woman was bailed and ordered to surrender her passport.
The school cannot be named to avoid identifying the woman.
