A school cook told a court dinner money had gone missing but she had not taken it.
Paula Kester is accused of stealing £60,000 over a period of four years from St Hild's School in Hartlepool where she worked.
A jury at Teesside Crown Court heard dinners were paid for using pre-paid cards which pupils topped up by putting cash into machines at the school.
Prosecutor Martin Towers said Kester had the sole responsibility for preparing the cash taken by the machines for the bank.
Kester is alleged to have regularly 'under banked' the takings, pocketing the difference.
The machines recorded what they had taken, but only Kester looked at the record.
Mr Towers put it to Kester that an employee in her position could have stolen money.
Kester replied she could have done, but had not.
Mr Towers said the investigation had identified seven successive Fridays when no money was banked.
"Where you in the habit of stealing the takings each Friday?" Mr Towers asked Kester.
She replied that she had not stolen any takings.
The court was told of many days in which the machines recorded more money than Kester had prepared for the bank.
"I didn't notice," said Kester. "Had I noticed the difference I would have done something about it.
"I accept there are discrepancies in the records, it does look like money has gone missing.
"But I didn't know that at the time, only since the investigation."
The jury heard the prepayment machines were unreliable and broke down.
Kester would sometimes fix faults herself by removing a stuck note or coin, or she would arrange for the machine to be repaired.
She agreed with Mr Towers that the faults may have accounted for small sums of money going missing, but not £60,000.
The court heard £20,000 in cash went through Kester's personal bank account over the four-year period.
Kester said she had sold cars for cash, and had had some cash Lottery wins.
She claimed she been given a cheque compensation payment for an accident which she had turned into cash 'to pay into the bank'.
Police found a briefcase hidden in Kester's wardrobe containing hundreds of pounds in five pound notes.
"They were brand new £5 notes we were saving for the kids," she told the jury.
"Those notes didn't come out until after I'd left the school."
Kester, 53, of Percy Street, Hartlepool, denies four charges of theft between September, 2012, and April, 2016.
The case continues.