The Frederick News-Post (http://bit.ly/1yTXRXX ) reported Friday that Carla McFarland says she found the little plastic baggie in a container along with the French fries she bought Wednesday in Frederick.
McFarland says she complained to a manager and called police. She says a manager later told her an employee had been fired after saying the bag must have slipped from her apron.
Franchise owner John Louderback confirms that the employee no longer works there.
The Frederick County Sheriff's Office says it's investigating the matter.
McFarland isn't laughing. She says her two young children were in the car, within easy reach of the bag.
Sonic Corp. is based in Oklahoma City.