Nelson was assigned to hear the case one day after an appeals court ruled Zimmerman should get a new judge in his trial for killing unarmed teen Trayvon Martin. A three-judge panel of the 5th District Court of Appeal ordered Circuit Judge Kenneth Lester Jr. off the case for having written in a July 5 ruling Zimmerman was "manipulating" the court system.
Lester set bail at $1 million in that ruling but accused Zimmerman of showing "blatant disregard for the judicial system."
Nelson, 58, is a 13-year veteran of the bench with a reputation for hard work and handing out long sentences, the Orlando Sentinel reported.
She was appointed in 1999 by Gov. Jeb Bush.
In his argument for a new judge, Zimmerman's attorney, Mark O'Mara, said he did not believe Lester could treat his client fairly.
"Although many of the allegations in Zimmerman's motion [for a new judge], standing alone, do not meet the legal sufficiency test, and while this is admittedly a close call, upon careful review we find that the allegations, taken together, meet the threshold test of legal sufficiency," the appeal court judges wrote.
Prosecutors argued Lester's remark was based on evidence Zimmerman and his wife had been hiding assets and were not truthful about that during an April bond hearing.
Zimmerman, 28, shot and killed Martin, who was 17, in Sanford, Fla., Feb. 26. He has claimed self-defense.
Nelson is the third judge assigned to the case. Lester took over after Circuit Judge Jessica Recksiedler stepped aside in April.