Shamima Begum has spoken of the grief of losing her three children, her regrets about joining so-called Islamic State and claims she only defended the terrorist organisation in her first interview because she was "scared of other women in her camp".
Ms Begum left the UK aged 15 when she and two other east London schoolgirls travelled to Syria to join the so-called Islamic State group (IS) in February 2015.
In a documentary filmed over the past two years which aired on Wednesday night, Ms Begum is filmed along with other Western women, including US-born Hoda Muthana and Canadian Kimberly Polman.
The Return: Life After ISIS focuses on the women who are living in various degrees of statelessness in refugee camps in northern Syria.
Ms Begum has been in Al-Roj camp in Syria since at least February 2019.
In the film, which aired at the South By Southwest (SXSW) festival, the 21-year-old cries when talking about the deaths of her three children and says that she wanted to kill herself because of the grief.
On the death of her third child, Ms Begum says she stayed up all night with his body.
“He was my last hope, he was the only thing keeping me alive. I didn’t know how.
"That day I just cried for all my children. I cried for all of them. No one could help me, no one could do anything."
She also says the father of her children - a so-called IS fighter from the Netherlands - is alive and sent her a birthday card wishing her well.
Ms Begum says people wrongly "feel like I'm responsible" for the crimes of so-called IS but insists she did not know about or support the brutal crimes, such as rapes, tortures and beheadings.
She says she rejects IS's beliefs and that she was a “naïve” teenager who did not even “speak the language”.
The former London schoolgirl also addresses her comments in her first interview after she was discovered in a camp, in which she told journalists she "doesn't regret" joining IS.
Ms Begum says she was forced to say this as she was scared other women would come "into my tent and kill me and my baby".
Explaining why she travelled to Syria to join IS in the first place, Ms Begum describes herself as the "black sheep in the family" growing up who had a difficult relationship with her mother, who didn't make her feel loved.
She says she turned to the internet and after watching videos of Syrians being bombed "felt really guilty" and wanted to defend Muslims who were suffering.
She said it made her "sick to my stomach that this was going on in the world and no one is doing anything about it.
"I always wanted to be part of a Muslim community because when I was young, I felt like I was an outsider in my community.
"So I just wanted to be a part of something. My friends started practicing (Islam) and they helped me come into the religion as well.
"And it just started with like learning my religion. And then it turned into wanting to come into Syria, wanting to help the Syrians."
Amira Abase and Kadiza Sultana, the two schoolgirls Ms Begum left Bethnal Green with, have both been killed in airstrikes.
Last month, the Supreme Court ruled Ms Begum could not return to the UK to pursue an appeal against the removal of her citizenship.
ITV News filmed Ms Begum shortly after this ruling but stayed silent.
Watch Global Security Editor Rohit Kachroo's report after Shamima Begum was filmed following the Supreme Court's ruling
Her citizenship was revoked on national security grounds by the Home Office shortly after she was found, nine months pregnant, in a Syrian refugee camp in February 2019.
Ms Begum is challenging the decision to remove her British citizenship and wants to be allowed to return to the UK to pursue her appeal, but the Supreme Court have prevented this.
The prospect of being able to mount an effective appeal from a Syrian refugee camp seems a remote one for Ms Begum.
In the documentary, Ms Begum accuses the British government of "making up" stories that she worked for Hisba or the so-called IS morality police as an excuse to keep her out of the country.
She tells the filmmakers: "It makes no sense how ISIS would let a 15-year-old with no Islamic knowledge work for Hisba when I don't speak the language, I don't really have any credentials or anything.
"So I don't know why I'm being accused of this. I think my government just wants to make me look bad and they couldn't find anything, so they just made it up."
The documentary was largely filmed before the Supreme Court ruling and in it, Ms Begum asks the UK to give her a "second chance".
“I would say to the people in the UK to give me a second chance because I was still young when I left,” Ms Begum says in the film.
“I would ask that they put aside everything they’ve heard about me and just have an open mind about why I left and who I am now as a person.”
In a lighter moment in the film, one of the other interviewees asks Ms Begum what she would do first when she got back to the UK.
Laughing, she replies: "Eat a nice big Subway, a foot long with meatballs. Just leave me with it."
The film was directed by Spanish filmmaker Alba Sotorra Clua who said in an interview with womenandhollywood.com she was drawn to the subject because she saw the "human face" of the suffering behind so-called IS.
She said: "This is a film about dialogue, understanding, and forgiveness as a way for peace that challenges the viewer to listen without judging.
"I hope the audience, after watching this film, will change their perspective on what is the responsibility of our governments regarding thousands of women and children in detention camps in north-eastern Syria for more than two years."
Ms Clua said that the crew were all female and that the first days of filming were "tense" because the team did not want to share food with the women in the camp and some even "feared that the food could be poisoned" and were "incredulous" with what the women were claiming to them.
She continued that the women in the camp did not trust the filmmakers at the beginning either, but over time the "walls of fear and pain fell to make room for an honest dialogue".
The film was in part funded by Sky TV which will show it in the UK later this year.