Take a cold shower. Read the Bible. Find a boyfriend.
I'm only kidding. If you're attracted to her, there's no reason to fight against the feeling. I know how you feel about being reluctant to try and start a relationship with a friend. If it doesn't work you end up without a partner nor a friend. If I were in your situation I would sort of let things ride out a bit. See how things unfold over a certain amount of time. And if you decide to make a move, make sure it's subtle. Don't dive on her in the showers (but if you decide to do this, bring a camcorder?)
But you probably knew most of this already. I hope I was a help, even in the slightest way.