Shamima Begum’s return to the UK has been put on hold after the government was given permission to take the case to the Supreme Court.
Begum, now 20, was one of three east London schoolgirls who travelled to Syria to join the Islamic State (IS) terror group in 2015.
She lived under IS rule for more than three years before she was found, nine months pregnant, in a Syrian refugee camp in February last year.
Then-home secretary Sajid Javid revoked her British citizenship on national security grounds later that month.
Earlier this month, Court of Appeal judges ruled that Ms Begum should be allowed to return to the UK to challenge the decision, saying it was “the only way in which she can have a fair and effective appeal”.