An Australian woman trapped with her two young children in a refugee camp for Islamic State group families says her daughter needs urgent medical care and she wants to come home.

Key points: An Australian woman believed to be Zehra Duman is being held at the Al Hawl refugee camp in Syria with her children

An Australian woman believed to be Zehra Duman is being held at the Al Hawl refugee camp in Syria with her children Prime Minister Scott Morrison says Australians who support terrorism overseas need to be aware of the consequences

Prime Minister Scott Morrison says Australians who support terrorism overseas need to be aware of the consequences About 30,000 people have fled northern Syria as Kurdish forces launch their final assault on Islamic State territory

The woman refused to confirm her identity, but it is believed she is 24-year-old Zehra Duman from Melbourne.

She is being held at Al Hawl refugee camp in north-east Syria.

In an interview exclusively obtained by the ABC, the woman said she wants to bring her two-year-old son and six-month-old daughter back to Australia.

"Both of my kids are sick. [My daughter is] very malnourished, she's … very skinny," she said.

"I have no money, I'm not allowed to have money, they don't give us food here and they don't let us contact our families."

The Australian woman said her daughter's life was in peril.

"My daughter needs milk and I don't have money to buy her milk. I don't know what to do now," she said.

She also said that she wants to come back to Australia.

"I want to go back to my country. I think everybody's asking for that because I'm an Australian citizen.

"I understand the anger that they have towards a lot of us here, but the kids don't need to suffer. My kids have a right at least to be treated like normal kids," she said.

But Prime Minister Scott Morrison said those who go overseas to support terrorists need to be aware of the consequences.

"They have to take responsibility for those decisions to join up with terrorists who are fighting Australia. I'm not going to put any Australian at risk to try to extract people from those situations," he said.

"There is a process for us to deal with them under Australian law, and they will face the full force of Australian law should they be in a position to seek to come back."

'There was no way out'

The Australian woman said she tried to flee the Islamic State (IS) group for two years and return to Australia, but she had no way of getting out.

"It's very dangerous to leave like that. If you get caught from one side or the other side, it can put you into a lot of trouble," she said.

"People tell you 'oh, just go walk over', but you can't do that. It's not safe.

"You're looking for a way out, and there's no way out until somebody makes a way for you.

"Nobody understands that you cannot leave that place without money, and no money is allowed to be sent in, so you're kind of left in a hole."

The Australian woman's story appears to match that of Zehra Duman — a 19-year-old who left Melbourne to join IS in November 2014.

Ms Duman moved to the IS Syrian capital of Raqqa and married Australian fighter Mahmoud Abdullatif.

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She was a vocal supporter of IS's violent rhetoric on social media, as well as an effective recruiter.

In 2015 Ms Duman, calling herself Umm Abdullatif Australi, posted a picture of a woman holding an automatic rifle, with the caption: "catch me if you can".

An account linked to Zehra Duman tweeted "catch me if you can" in 2015. It has since been suspended. ( Twitter )

A Twitter account believed to be operated by Ms Duman was suspended in 2015, after she called for violence against "kuffars", or non-Muslims.

It's believed that Zehra Duman made these threats on Twitter in January 2015 ( Twitter )

In February, the ABC obtained exclusive footage of a woman believed to be Ms Duman and her daughter in Syria, who then appeared to be healthy.

The video was filmed by American humanitarian worker David Eubank in northern Syria.

Australian woman Zehra Duman (centre) with aid workers from the Free Burma Rangers in Syria. ( Supplied )

The woman in the refugee camp, who refused to confirm whether she was Ms Duman, said she followed her boyfriend to Syria.

"I knew him from when I was a teenager from school," she said.

"I started speaking to him online — got back in contact with him — and he was religious and stuff. I wasn't Muslim my whole life. I came here to marry him," she said.

"Then when you come, your husband dies and there's no way out. If you're going to get out, maybe you're put into jail."

After Abdulatiff's death, Ms Duman married another IS fighter who died two months ago in the battle for Al Soussa, a town near Baghouz.

"My husband got killed and I was just looking for a way out. I just packed my bags, and I walked out with my kids by myself," she said.

'I am an Australian citizen'

"I am an Australian citizen," the woman says. ( ABC News )

Last month, the Syrian Democratic Forces (SDF) negotiated with IS to allow civilians to leave.

The woman believed to be Ms Duman left on a convoy and arrived at the processing area three weeks ago.

She said the journey from Baghouz to the Al Hawl camp was difficult.

"We were on the truck for two days. It was raining on us, there were no blankets and it was freezing. My daughter was cold, so I was just making her warm with my body heat," she said.

The woman claimed to have had no contact with the Australian authorities.

"I have not seen any embassy [official] or anything. We don't know what's happening. We're not allowed phones here, we're not allowed to talk to our families," she said.

"The world is talking about taking us back and whatever and we're just really [praying] that we can get out of this place.

"At the end of the day, we're human. We have human rights."

She said her family knows she is in the camp because she contacted them before she left Baghouz.

"They're trying to see what's going to happen with me, it's a hard situation," she said.

Authorities in northern Syria have been overwhelmed by about 30,000 IS family members who have come out of Baghouz in recent weeks.

They said they provided three meals a day to the women and children, and they were doing their best to give basic medical care.

But the Kurdish authorities said they desperately needed help from western nations, and they wanted countries like Australia to step up and take back their citizens.

A spokesman for the Syrian Democratic Forces, Mustafa Bali, said they have requested help from Western governments, but they have not received a response.

"We understand their concern. If there's an Australian terrorist here and we send them back, they could be in jail for a short time, and then they'll bring danger to the people in Australia," he said.

Scores of children have died in the camps.

Earlier this week, lawyers for 19-year-old British IS bride Shamima Begum announced that her newborn son had died.

The baby's death has triggered a debate in the UK over whether to allow the children of IS fighters to return to their parents' home country or countries.