On Wednesday, Judge Rom Vinograd in the Jerusalem District Court ordered Leifer's release from custody and that she be placed under house arrest.
He allowed 48 hours for his decision to be appealed.
Early Friday Australian time, Supreme Court Justice Anat Baron ordered that Leifer's release be delayed as she considers appeals made by both the prosecution and defence.
Victim supporter Manny Waks attended the hearing and said he felt "cautiously optimistic" the judge will reverse Leifer's release.
"I hope and expect that Leifer will remain in prison until the end of proceedings against her," he said in a statement on Friday.
"Most importantly, Leifer will remain in jail for now."
The court hearing comes after Victorian Premier Daniel Andrews wrote to Israeli Prime Minister Benjamin Netanyahu on Thursday, reiterating his view that Leifer must be extradited "in order to face the scrutiny of the criminal justice system in Australia".
Mr Andrews said the decision to grant bail "defies explanation".
"I am hopeful that in writing to you, the Israeli justice system can move quickly to right this wrong. Victims and their families deserve nothing less," his letter read.
Federal Attorney-General Christian Porter said he would travel to Israel in the coming months to raise the matter "personally and directly" with his counterpart.
"Given our request was made in 2013, the length of time that Israel is taking to finalise Australia's extradition request is regrettable," Mr Porter said in a statement.
"Ms Leifer is facing very serious criminal charges - it would be better for all involved that these charges are resolved."
Alleged victim Dassi Erlich described the bail ruling as a "massive betrayal of justice".
Leifer's bail conditions would include staying with an appointed family member, reporting to police and attending a medical facility for treatment.