Short version:
Just ask her out, and be unambiguous.
You'll make other friends.
Longer version:
What you don't want is this situation where you don't ask, so you're now friends, and she finds a mate, and you're sitting there saying "oh it's cool, we're just friends" but the inner part of you that cannot lie is fucking crushed, so you spend months in a depression you can't explain (because you won't be honest with yourself), and all the while, you're missing out on many really nice people with whom you could have had something real and reciprocal. (Hahaha. Wow. Suspiciously specific! Well, I don't mind admitting, because I know I'm not the only guy who has ever had this happen to him.)