Pak'n Save Masterton also operates a Lotto kiosk, proceeds from which were brought daily to the cashier's room.
There, a new float would be made up for the next day, and the rest of the cash set aside to be banked.
Cummings would skim the funds from this banking and throw away the ledger with the amount to be banked.
Mr Peters said Cummings "only took funds on Sundays, which was the only day that she was working by herself".
The thefts continued between May 2009 and October 2011.
Cummings initially tried to cover her offending but when confronted by the manager, admitted it.
When police interviewed her, Cummings admitted the offending and explained how she had done it.
She said she believed she had taken $65,000.
Cummings' lawyer, Ian Hard, said she admitted taking up to $90,000 but did not believe it was more than that.
Mr Hard said it appeared the total included any cash discrepancies during the time period, and these may have been from other causes.
As Judge Bruce Davidson considered a media application to take photographs in court, Cummings broke into sobs and was comforted by a companion.
Judge Davidson remanded Cummings until May for a pre-sentence report, to include reparation and the option of home detention.
