Girls: is she blowing me off?

In highschool, there is this girl that i have been glancing at for a few months. I used to catch her looking at me a lot, and still do, but not as much anymore. These last few weeks, I've been saying hi to her, and she always responds with a wave and smile, then moves on; nothing more. Also, during these last few weeks she has been less fidgety and more relaxed when around me. And then a week ago, I asked her, "Can I have a moment with you." She then said that she had to go to the bathroom. At the end of that day, while I was walking out of school, her friend was walking right behind me. I then hear her literally running, thinking at first that she wanted to talk to me. She then starts complaining to her friend about how she missed her bus to a soccer game. Is she ignoring me? The thing that really gets me is that she never actually stops to talk to me but she still looks at me. What is going on?

Also, does she probably know that i like her?