Lots of people on here seem to think she hasn’t shown remorse but her lawyers say otherwise. She said she is ashamed according to them.
Also, highly unlikely she’d show any remorse while still living within reach of Isis, given that there are reports of a girl trying to leave and being beaten to death.
Even so, remorse doesn’t affect your citizenship, there are plenty of people who have committed terribly crimes in this and other countries and don’t feel - or have to show - remorse in order to keep their citizenship.
From the Standard: “The fact of the matter is this - that Shamima, as with other British women and children, is arbitrarily detained in a prison camp in north east Syria," her lawyers said in a written statement on her behalf.
"It is not a refugee camp - those detained are unable to leave and the conditions have, with ever greater urgency, been categorised by every international body as well as by the UK courts in Shamima's case itself, as constituting torture and inhuman treatment."
Ms Begum has admitted knowingly joining a proscribed organisation. She said that she was "ashamed" to have done so and regretted it.”
It is not making excuses to say that she was a child groomed at the time. She’s very obviously being made an example of, as other posters have said hundreds of male fighters have been allowed back to the UK.