No doubt she was brainwashed.
Then again she could have easily come to the same conclusion by living her life by the same standards as Mohammed. A religion is as good/bad as the founder, and Mohammed was a bad guy.
Sure, he was 'peaceful' at first, but as he went on and consolidated power, he became much more violent and less tolerant of those who disagreed with him. He had people murdered, beheaded, and showed contempt and disrespect to other religious beliefs, most notably Jews and Hindus.
I don't know how his actions can be seperated from the religion he created.