Shamima Begum - the teenager who left the UK to join the Islamic State group in Syria - has given birth, her family have been told.
Their lawyer released a statement saying Ms Begum and her child - a boy - are believed to be in "good health".
Ms Begum, who was found last week by the Times in a Syrian refugee camp, has said she wanted to return to the UK.
The 19-year-old told Sky News from the camp "a lot of people should have sympathy towards me".
"I didn't know what I was getting into when I left," she said.
She said she made a mistake "in a way" by going to Syria, but added: "I don't regret it because it's changed me as a person, made me stronger, tougher.
"I did have a good time there. It's just that then things got harder and I couldn't take it anymore."
In an interview with the Times, published on 13 February, Ms Begum said she was heavily pregnant and wanted to come home to the UK for her baby's health.
She also said she had two children who had died in Syria.
The family's lawyer Mohammed Tasnime Akunjee told Radio 4's The World This Weekend that the family were informed about the birth in a phone call from a translator at the camp and that they had mixed feelings about it.
"They are obviously very happy and joyous that Shamima has successfully given birth and that she's healthy," he said.
But he added that following the death of Ms Begum's other two children, the family were "very concerned" about the baby's health and wanted both her and the child to return to the UK.
The lawyer insisted that the baby was "no threat" and that legally Ms Begum was allowed to return as a British citizen.
Cabinet minister Jeremy Wright told BBC's Andrew Marr programme that the baby's nationality was "not straightforward".
The culture secretary, who was previously attorney general, said the first priority was establishing the health of her and her baby.
"But in the end she will have to answer for her actions. So I think it is right that if she's able to come back to the UK that she does so, but if she does so she will do it on the understanding that we can hold her to account for her behaviour thus far," he added.
Debate continues over whether Ms Begum should be stopped from returning to the UK, with Home Secretary Sajid Javid writing in the Sunday Times that he would "not hesitate" to prevent the return of Britons who travelled to join IS.
He added: "The difficult challenge we now face is what we should do about those who are still seeking to return."
Under international law, the UK has an obligation to allow a British citizen who does not have a claim to another nationality to return.
However, the government does not have consular staff in Syria and has said it would not order its personnel to risk their lives to help someone who joined a banned terrorist group.
If Ms Begum was able to reach a British consulate in a country with a recognised government, it is thought security chiefs could "manage" her return, while investigating her actions.
Ms Begum and two other schoolgirls, Kadiza Sultana and Amira Abase, from Bethnal Green, east London, left for Syria to join IS in February 2015.
She told The Times that Kadiza had died after a house was bombed, but the fate of her other friend is still unknown.
In the interview, Ms Begum said she had escaped from Baghuz, Islamic State's last stronghold in eastern Syria, two weeks ago, but her husband - a Dutch convert to Islam - surrendered to a group of Syrian fighters as they left.
IS caliphate 'ready to fall'
Meanwhile, US-backed Kurdish forces continue an assault on the last pocket of the Islamic State group's territory on the Syrian side of the Iraqi border.
US President Donald Trump told the UK and other European allies to take back and put on trial more than 800 IS fighters captured in the final battle against the group.
The IS fighters are being held by the Kurdish-led forces.
Mr Trump added that the IS caliphate was "ready to fall".
A former head of the British Army, Lord Dannatt, backed Mr Trump's calls, saying Britain had a "responsibility" to those who left to join IS, including Ms Begum.
Speaking to Sky's Sophy Ridge on Sunday, he said they should be treated "fairly and firmly", adding it was important to show "a bit of mercy" to help prevent others being radicalised.
Lord Dannatt said: "It's not right to say 'the Americans can take her and the other fighters and stick them in Guantanamo'."
But he said it was a mistake to think IS was "100 percent defeated".
"The ideology, the thinking, the support behind it - that is going to continue. And that will remain the struggle for this generation; perhaps even the next generation as well."