U.S. Magistrate Judge Donna Ryu also said Noor Salman, 31, is not dangerous and there is no proof she has ties to the Islamic State group or holds extremist views. Her husband, Omar Mateen, pledged allegiance to several terror organizations during last year's attack that left 49 people dead at Pulse nightclub before police killed him.
"She herself is not charged with providing material support to a terrorist organization," the judge said, noting that Salman has no criminal record and that friends and former teachers called her "peaceful and nonviolent."
Salman has been charged with helping Mateen plan the worst mass shooting in modern U.S. history and lying to investigators. She has pleaded not guilty and faces life in prison if convicted.
She won't go free immediately, with the judge putting her order on hold for at least two days to give prosecutors time to appeal.
They have said Salman accompanied Mateen on scouting trips to the nightclub and other possible targets - including a Disney attraction. They say she told FBI agents that she knew Mateen was planning the attack.
The judge said Wednesday that prosecutors have provided no evidence. They have not offered transcripts, recording or video of Salman's 16-hour interrogation, which she faced without a lawyer in the hours after the June 12 attack, Ryu said.
Prosecutors will file their appeal with a federal judge in Orlando, where Salman is charged and where any trial will be held. One has not yet been scheduled. Prosecutor Sara Sweeney declined comment outside court.
If released, Salman will live with her uncle in the San Francisco Bay Area and be required to wear an electronic monitoring device. She can only leave the house for court appearances, meetings with her lawyers and doctor's appointments.
Salman and her young son had gone to live with her mother in suburban San Francisco, where Salman was arrested in January. The mother and uncle each pledged their homes as collateral to secure Salman's release.
Salman's attorney, Linda Moreno, said it is unusual for bail to be granted in terror-related cases.
"It's extraordinarily rare and a statement of the government's case," Moreno said.
Prosecutors say Salman initially said she didn't know anything about the attack but later told investigators that Mateen abused steroids, was "pumped up" on that night and said "this is the one day" as he walked out the door.
Sweeney also has said that the couple ran up $25,000 in credit card debt and spent $5,000 in cash in the days before the shooting. Among the purchases was an $8,000 diamond ring for Salman. They also made Salman the death beneficiary of his bank account, prosecutors said.
Orlando Police Chief John Mina said he was disappointed Salman is being released pending trial. "Nothing can erase the pain we all feel about the senseless and brutal murders of 49 of our neighbors, friends, family members and loved ones," Mina said. "But I have full faith she will ultimately be brought to justice."
Associated Press writer Michael Schneider contributed to this report from Orlando.