I agree with everyone else. She might as well be holding up a sign that says "I have a thing for badassy!" I remember being your age, and being unsure of myself and what the outcome of any given situation will be, just to find out later in life that it is ok to be unsure. If you do make a move, the worse thing that is probably going to happen is she'll pull her head away and it will probably be a little uncomfortable for a minute. If that's the case then just explain you misread her signals, and probably no harm done. But then again, what's likely to happen is she will kiss you back. Now, I know you are having a problem with confidence, but the best way to deal with that in my experience is to just go for it, and belive me my friend it will get much easier each time thereafter. Even if you get shot down, you will find out it isn't as bad as your busy mind has made it out to be. I think you know how she feels about you, you just need to decide if you want to believe yourself.
Just my $0.02.
ViSionS
Problems cannot be solved at the same level of awareness in which they were created. --Albert Einstein