I slept with a girl twice and now she doesn't know what she wants. Help?

I have liked this girl for a few months. Before I even came into the picture, she liked another guy who told her he didn't know what he wanted (they never officially dated, but they had sex). She hinted to me that she would want to date me if it weren't for him, but I did not want to sit and play 2nd fiddle to another guy so I did my own thing. We still hung out though. Eventually they messed up and I slept with her twice. Everything seemed to be going my way but apparently she told her best friend that she was upset that I didnt text her all day until midnight. I called her about it today and she said she just doesnt know what she wants to do with me. I told her to come back to me when she knows what she wants to do because I'm not gonna be played with like she was with the other guy. Any ideas why she feels this way?