The family of Shamima Begum – who left the UK to join the Islamic State group in Syria – have told the home secretary they are going to challenge his decision to revoke her UK citizenship.
In the letter to Sajid Javid, seen by the BBC, they say they “cannot simply abandon her” and that her status is “a matter for our British courts”.
But they added they were “sickened by the comments she has made” recently.
They also asked for assistance in bringing her newborn baby to the UK, BBC reported.
Ms Begum, who left Bethnal Green, east London in 2015, is living in a refugee camp in northern Syria and gave birth to a son last weekend.
In an interview with the BBC on Monday, she said she did not regret travelling to Syria, though she added that she did not agree with everything the IS group had done.
She told the BBC she was “shocked” by the 2017 Manchester Arena attack – which killed 22 people and was claimed by IS – but she also compared it to military assaults on IS strongholds by coalition forces, saying it was “retaliation”.
The letter, written by her sister Renu Begum on behalf of the family, says: “We wish to make clear, that along with the rest of the country, we are shocked and appalled at the vile comments she has made to the media in recent days.
“These are not representative of British values, and my family entirely reject the comments she has made.”
Renu Begum says the family made “every fathomable effort” to stop Shamima Begum from getting into Islamic State territory in 2015.
“That year we lost Shamima to a murderous and misogynistic cult.
“My sister has been in their thrall now for four years, and it is clear to me that her exploitation at their hands has fundamentally damaged her.”