Am I making her uncomfortable? Or is it fine?

I have met a girl who I really like, and I spent about 20 minutes talking to her today. She seemed happy and, as usual, talked in these awfully big phrases she talks in with no sign of her voice speeding up or anything. However, I am worried because of something I read on the internet.

Last week, she sat with me abruptly and was very friendly, all the while playing with her hair. This Monday, I asked for her phone number after getting a little worried when she talked to me, smiling, but her body and eyes pointed away from me (despite still turning to me directly at times).
When I asked for her number, she immediately responded, turned to face me, happily wrote down her number on my phone and added her name. I then went away, but as I watched her, she walked rather slowly away from me.

Today, we talked before and after lectures and then spent some time talking outside which surprised me when it turned into 20 minutes of a reciprocal conversation. She really helped me with my project. I tried to watch what she was doing. Some things worried me, some things didn't.
The thing that worried me the most is that, for the most part, she was turned away from me slightly and not looking at me, instead turned to the side. At other times she would look at me with a smile and her toes turned towards me, but still. I read a lot of things about this which alarmed me.

As she did so, she kept smiling with that lovely toothy ear-to-ear grin she has, periodically laughed at something I said, constantly stroked her hair and showed no signs of disinterest in her voice even after she previously told me she 'had a few minutes'.

The one thing she never did was cross her arms or her legs, or respond in short, automatic yes/no phrases. On the contrary, she spoke in giant sentences and smiled all the time, never backing away from me or anything, etc.

Am I making her uncomfortable, or is she just nervous?
I feel alarmed by her not making eye contact all the time, but she also does contradictory things like hair playing and talking in massive sentences, which I heard are a good sign.
I remember I acted like that myself around girls I had a crush on, never making eye contact but instead touching my shirt collar, all the while looking to the side (I was very nervous, but liked her a lot)

The conversation ended when she said she needed to go (rather calmly) and we ended there. I went behind her to go to my lecture, and she stopped and began looking for me. She found me with her eyes, said bye and rapidly that turned into another massive sentence, and then left

This girl is extremely friendly and polite, which makes me especially worried because I am bad at reading emotions and don't want to make her uncomfortable, because *I am crazy about her*. And the last thing I want is for her to be uncomfortable with me. I on the contrary want to be someone who she can trust and turns to when she needs help.
Then again, when I asked for her number she looked directly at me and happily wrote it down for me, reacting instantly.
All in all, I really like this girl, who I find fascinating and smart, and really don't want to lose her. Should I be worried?

(Watching her actions, she seems rather shy and non-social, often vanishing into thin air after lectures before we began talking, and I have personally seen her smile and wave at her friends despite not even looking at them)