Why don't you just touch her leg and see what she does?! kidding.
Well I think the best way to do it is to just ask her but if you want to start off by playing these silly games (I know it's just because you're worried and whatever) then that's fine. I know where you're coming from, i've been in this position before, you analyse everything they do. The thing is, you're never going to know unless you just ask her (even if you make out, she could put it down to being upset/drunk/odd mood).
Either you hurt yourself more and not say anything, hoping she'll say something or you finally see how she feels.
You never know, she could be posting on another site saying the same about you!
Does she know you're bi? x
p.s. sorry about rambling.