I can't figure out if this girl is uninterested or shy. Please help?

So, there's this girl (F18) I noticed looking at me a lot a few months ago. At first, I didn't think it meant anything. But then, I saw her staring my way, even when she wasn't looking directly at me. Just to be sure, I did a little test and I confirmed it.

After that, I decided to talk to her. I mustered the courage, asked a question, hoping to extend. But she hit me with a short, kind of mean answer that hurt. I tried to move on, but then she surprised me. One day, she started a conversation, seemed a bit nervous and anxious, but ended it with a smile, then after that we cached each other's eyes and we made eye contact, I smiled, she smiled back.

Still, things got confusing. She ignores me completely when we're close, but I catch her looking at me from across the room and she glances away. I had moments where our eyes met, and it lasted like 5-6 seconds - no smiles or anything. It left me scratching my head whether she's really shy or not. She still gives quick answers, and I haven't seen her talking to any guys for like six months. She hangs out with two other girls, and two months ago, all of them used to stare at me when I walked by. It's weird.

Oh, and there's one more thing. About three weeks ago, we were both leaving, going our separate ways. I walked a bit and, for some reason, turned back. Guess what? She was right behind me, walking the same way. I looked at her, but she acted like I wasn't even there, totally ignoring me. Then, when she moved a bit far away from me, she turned back and looked at me. She did that a bunch of times. It's kinda puzzling, you know?

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2 mo
by the way, we used to greet each other, but then, after I noticed that she avoids eye contact with me up close, I stopped greeting her. I thought she hated me
I can't figure out if this girl is uninterested or shy. Please help?
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