Doug,

Sky might be right, but I also think you might be reading waaaaaaaaaay too much into this "look". If she didn't say anything to you or you to her that indicates interest on either side, I would stay away from the eyeball cues. These days it can be very dangerous to assume about anyone's sexual intentions.

That said, don't necessarily blow her off, either. Try talking to her again. She may not have been in a relationship at all, but may have had something on her mind at the time (I know I go to the gym to blow off steam from work - the LAST time I ever want somebody to approach me) or may have been enjoying the single life and not looking for anything at the moment. Things change. I'd say don't assume from the looks, try chatting her up again maybe as you leave the club and if she ignores you again, disregard any looks from her sexual or otherwise.

some of it's magic
some of it's tragic
but i had a good life all the way......
~jimmy buffett