I don't understand what you're doing here. By this point, it was very very clear what ISIS were like. They did not hide it. Instead, they revelled in it. Their propaganda videos had some lovely music yes, some lovely imagery but it also explicitly contained references to what they were doing. Including stuff like beheadings.
I don't know, if I'm moving to a new country, I would do a little reading. Oh they behead people? Oh they torture and use non muslim women as sex slaves? Interesting. Probably not going to that country then.
What videos was she supposed to be seeing instead? Where did ISIS try to hide what they were doing?
The problem is that she liked that aspect of what they were doing, could happily tolerate it or perhaps decided this was somehow a conspiracy. One of my wife's friends is from Mosul was certainly in the latter category. Did not believe for a second any of the videos were real, any of the stories were real. When they first rolled into Mosul, she thought of them as heroes, revolutionaries, removing them from Shia rule. It took radio silence from her family still there for months and them eventually managing to sneak out a few messages here and there with the atrocities they were committing before she decided to believe the truth.
Of course, like Begum, her family had the luck to be Sunni, rather than Shia, Yazidi, Christian etc and weren't subjected to torture, rape and slavery and death unless they poked their head above the parapets.