I'm now entering this debate because of this news:
https://www.theguardian.com/uk-news/201 ... or-targets
My opinion is very much that terrorist groups do their recruiting and grow in stature by fuelling hate. And the only way you can reduce their impact is by the opposite of hate: compassion and empathy.
Thinking about this case in light of everything around it, the only sensible thing that appears to me is to bring her back to the UK, treat her well, talk to her constantly, understand what her pain points were, what caused her to leave, what caused her to say what she said, and to try and find a way to help her overcome those problems.
The only way you can remove terrorist organisations from the world is by treating the people they want to radicalize with respect, empathy and compassion, no matter how repulsive their views may be.
The leaders of those terrorist groups rarely care about the issues they allegedly stand for, either, they only care about themselves. But they're very good at manipulating others. So, as a government, you need to make the groups at risk of being radicalized feel at home, welcomed, part of a great unit.
Unfortunately, that goes against the political methods of the day, which are akin to fucking 10-man rugby: the simplest possible way to win, so everyone does it.
And until we have a BIG change in political power somewhere, and a revolution, we will continue down this route of hatred, radicalization, more and more terrorism, hate crime, destruction of livelihoods, and so on.
So, stop and take a look. Of course she should be bought back to the UK. She needs someone who can take care of her. It doesn't matter how disgusting her views seem to you, she needs someone to help her. And desperately. And by turning her down, the UK government is showing itself for what it is: terrorists.