I have a friend who is pagan, who admits to being irrational. But it makes her feel good, so it's okay for her to believe in it. I love her, but I admit to staring at her for a whole five minutes in silence.
Rachel, when I define the word rational as economists do, as referring to the benefits and costs that result from a choice, the only rationality I see in religion, especially xianity, is the kind that prevails in a dominant/submissive relationship.
One day about thirty years ago when I was still in transition, after a talk by a retired college professor I remarked that I wasn't comfortable with the superior/inferior aspect of xianity. His reply shocked me; he said "That's what I like about it."
Your pagan friend might be more rational than she knows.