I don't think her books are about Islam or Bush. But as it often happens with the real art, they transcend the here and now. Her books are about good versus evil. As "simple" as that. And here comes my BUT: because progressives reject this "simplistic" notion of good and evil, her books become conservative almost by default (regardless of what she herself might have in mind, as long as she keeps writing real literature).
I agree with you here.