OK. Here are the facts.
You somehow creeped her out. You obviously can't answer that, but for some reason you made her uncomfortable. Remember, women get hit on ALL the time, so she somehow sensed that you were hitting on her and she felt creepy. Maybe it was cause you stared at her. Tell you what, find a girl who is a friend and be direct with them. Tell them what happened, even act it out.
Ask her if she felt creepy or if there is anything creepy about what you did, said or even looked at. Women are amazing at giving feedback to improve your game. Also find a guy friend and do the same. The insights are priceless.
One time we had a client who was decent looking and totally cool. We approached some women and he just talked way to fast, had odd body language and just didn't seem congruent.
We had him slow down, smile and pause and fix a few things in his body language and he literally improved so much it was insane. He had no idea what he needed to fix, or how easy it was to fix. See, it is just really hard to see yourself, as others see you. You must get help. Bootcamps of course will do that (the good ones), but it can also be as easy as having some friends who are more socially in tune to watch you and provide feedback.
And by the way, don't trip over this one girl or incident. You will chat with thousands and thousands more.
Maybe you did everything right and she was a bitch... or maybe she was cool and you blew it with some minor things which can be easily corrected... either way it ain't a big deal.
Bill