"Joshua Boyle took Coleman" What makes you think he "took" her, as if she had nothing to say about it? Maybe she was the one who convinced him, or at least an enthusiastic follower? She could have returned home on her own if she had wanted to.

They were both determined travelers, this was to be their last stop in a long trip.

However, he does seem to have been "on the side of" islamic terrorists, and there are indications Boyle at least had converted to Islam, so they were most likely very very naive to say the least.