This woman should not be allowed back into the UK if possible IMO. She is a threat to this country, even if she does nothing herself, she will be imprinting her child with the same disgusting beliefs she holds. She willingly left this country to go and join this medieval organisation. She knows full well the barbaric actions they have inflicted on the populations they infest, yet she still supports them.
going by this article:
The UK can strip citizenship from people. She wont be left without a state. She has made her bed with the Islamic State, whether they are recognised as such or not.