They all CHOSE to leave civilized lands to go forth and deliberately, intentionally (mens-rea) commit MURDER – and against fellow muslims, even!
As self-determined murderous criminals, there is no way any of them should now be let back into civilized lands which obey the rule of law – because rights (to citizenship) can only come with corollary, concomitant responsibilities – by accepting the duty to obey that very same, Golden Rule of Law which most simply defines all morality as Do Not Attack First – a law which, by their own chosen actions, they have obviously breached, reneged on, and abdicated their responsibility to uphold by joining the very most attack-first-prone gang of criminals on the planet today.
And, as for their jihadi "ISIS Brides" - it really doesn’t matter if they were, as devalued women, “merely” aiding, abetting, and enabling the main criminals, as willing accessories to their crimes, by offering them support services, either.
Further, by becoming and remaining members of the world's oldest and largest ongoing crime and murder gang, their general membership alone re-presents the inherent threat of violence the gang itself presents, and is thus a crime on its own, despite that they may not have committed any other specific crimes themselves! That's why crime-gang membership is also a crime!