The employee — whose name was not released — found a wallet on the floor and snuck to the bathroom to take photos of the credit cards inside on May 24, authorities said.
The former employee then used the information to rack up charges totaling $3,097.39 Mansfield Township Police said.
The teen was arrested Jan. 15 and charged with credit card fraud.
She was released and is scheduled to appear in court.
Click here to follow Daily Voice Warren Hunterdon and receive free news updates.