Sounds like being sympathetic to the Palestinian cause didn’t do her much good once ISIS got their hands on her.
Yeah, the Palis and ISIS are two entirely different animals. Palis know that westerners can be useful in presenting their cause to the Western world, and so they are too valuable to just kill (as long as they are useful).
ISIS doesn’t care about that, because they aren’t looking for Western sympathy or support. Their goal is the caliphate, and so if you won’t convert and fight for them (or breed more fighters in the case of women), then they have no use for you.