Sonya Abbas, visited her 11 relatives at the al-Hawl camp in July.
They have been living at the sprawling camp that houses more than 60,000 detainees since the fall of IS in March.
Many of the women at the camp are hardline believers of the so-called Islamic State, including partners, widows and children of former IS fighters.
Save the Children urge Australian government to repatriate families of IS fighters in Syria
More than 60 Australian women and children are believed to be detained there and Ms Abbas urged the Australian government to bring them back.
"Bring them home, judge them here. Don't let them die like that," Melbourne-based Ms Abbas told SBS News on Tuesday.
"They're scared and frightened ... as much as I reassure them, I know I'm lying to them on the other line. I don't have answers for them, I feel helpless.
"I haven' t been able to sleep at night at all, how can anyone sleep just thinking. They're humans."
Ms Abbas' niece Sahra Ahmed, who has three young boys in al-Hawl, sent a voice recording, expressing her fear.
"I'm so scared, I don't know how much longer I can do this for ... They just found a woman's body in the toilets, she was all mutilated and cut up." Ms Ahmed said in the recording.
Australia has already repatriated some orphans, but Middle East analyst Rodger Shanahan said the issue was complex.
“The government has to do 2, it has to determine who is in this family and what their responsibilities are for them, from what we know, there are children at the camp to multiple fathers," he said.
“The other issue is that the government has to determine the security risk of the adults, and also whether they are able to gather enough evidence to be able to prosecute them when they come back."
Kamalle Dabboussy, whose daughter and grandchildren are being held in the al-Hawl camp, said the camp remained in Kurdish control and action could still be taken.
"The camp is still under Kurdish control, the border crossing is still open, action can still be taken but that is a situation of days rather than weeks," he said, in Canberra on Tuesday as he urged the government to intervene.
He also revealed two more Australians have been identified in the camp as a result of the increased media attention.
He said details about them were scarce, but they were very frightened.
"The mother appears to have been targeted by the radicalised women in the camps before. She's been beaten with metal poles," Mr Dabboussy said.
Her child is also believed to have shrapnel wounds.
Mr Dabboussy shared a recording of one of the women in the camp.
"Please don't let us fall into the hands of the [Syrian] regime. Everybody in the world knows the war crimes this guy does," the recording said.
"We're asking just as humans, just as regretful people. If this happens that's it for us. That's it for my kids."
Conditions have deteriorated since the withdrawal of US troops cleared the way for Turkey to launch a military offensive on rival Kurdish fighters.
Kurds have controlled the camp up until now, but after being abandoned by the US, they are focussed on defending their territory rather than managing IS camps.
They are expected to hand over management of the al-Hawl camp to troops loyal to the Assad regime which has shown no mercy to IS fighters.
While Kurdish fighters have been cooperating with Australian families and government officials on the release of foreign citizens, it's unclear how the Syrian government will treat them.
The new conflict has reshaped alliances in the region, prompting the Kurds to form a rushed agreement with Russia-backed Syrian forces.
IS fighters have also seized on the chaos launching several attacks with a senior official at the camp telling SBS Arabic24 that women loyal to IS in the camp were using basic materials to make bombs.
At least 750 people affiliated with the terrorist group are believed to have escaped a camp in Syria's north-east.
While the Australian government has expressed deep concern about the Turkish military offensive, it has not committed to bringing back its citizens.
Foreign Minister Marise Payne last week said the Morrison government won't speed up the evacuation of Australians from the camp, citing the dangers that would be posed to Australian officers that would have to be sent in.
There are also concerns some women remain loyal to IS and pose a security risk to Australia if brought back.
Australia has already repatriated some orphans but analysts say what to do with children whose parents are still with them is much more complex.