But unknown to school authorities the Lakes Heights Public School P and C treasurer was pocketing up to $150 each time to cover the spiralling cost of her gambling addiction.

It was only when suppliers of goods and services to the canteen complained to the principal about slow payments, that suspicions were raised and a Department of Education and Training (DET) investigation was launched.

In Wollongong Local Court yesterday, the 33-year-old mother of two pleaded guilty to embezzling the money between February and November 2008.

According to documents before the court, Janssen was treasurer from February 2007 to November 2008 and was responsible for day-to-day banking and book keeping of accounts, as well as the payments of suppliers.

In November 2008, the school principal was contacted by suppliers in relation to unpaid accounts for the canteen supplies, who then notified the department.

An audit conducted by the DET's Risk Business Analysis unit later revealed $13,870 in funds and stock were missing.

On November 25, last year, police went to Janssen's Berkeley home where she agreed to attend Port Kembla police station and participate in an interview.

She told police she had taken amounts between $100 and $150 a month from canteen takings between February and October 2008, before banking the remainder.

Janssen agreed the total amount she would have taken in that time did not exceed $1050.

She admitted to a gambling problem and said she would regularly put her weekly wage through poker machines, then use the canteen money to buy groceries and petrol.

When questioned in relation to the remaining missing stock and money, Janssen said she had "no idea where it went from the canteen", but had often heard other workers complaining volunteers at the canteen regularly gave away food to students.

Janssen will be sentenced on March 16.