The plea deal allowed her to admit to a lesser form of perjury and avoid a felony conviction, the Orlando Sentinel reported.
Zimmerman had been accused of lying in court during a bond hearing for her husband, George Zimmerman, after he had been charged in the 2012 shooting death of Martin in a gated community in Sanford.
The original charge, perjury during an official proceeding, was a first-degree felony that carried a possible five-year prison term and a $5,000 fine.
Shelley Zimmerman, a nursing student, would have been banned from applying for a nursing license for three years as a convicted felon.
The charge she pleaded to, perjury but not an official proceeding, is a misdemeanor punishable by up to a year in jail and a $1,000 fine.
She also will have to perform 100 hours of community service.
Her husband, who maintained he shot the unarmed 17-year-old Martin in self-defense, was not present in court.