In what way does she like me?

This is gonna be a long one so buckle up. First of all here's the situation, I skipped 2 years of high school to enter college early. As you might have guessed I was the youngest in my faculty. One day, during my 2nd year this girl started to pat my head. Not long after that I changed seats from my usual seat, only to have her come sit next to me. According to my friends, that has always been her seat, so I didn't think much of it. She would pat my head every time we meet and very often during the lecture. One of the first conversation we had was about past relationships, so I started to think that she might be interested in me. But then she later on compared me to a dog, so I figured that she like me in a big sister kind of way. My thoughts were further supported when my friend (who is kind of a gossip king, if that's even a thing) teased her about a senior she is interested in, to which she seemingly admit. I noticed she patted my head less often, although she still did from time to time. A couple of months went by and our faculty had a dinner event. After the event, she offered to drop me off at a station since she drove to the event. She kept saying that her driving skills isn't that good. Here's the part I'm confused about; during the ride, she was seemed to be kind of nervous. For example, she forgot to switch gears pressed the wrong thing etc. I think she thought I was feeling nervous after seeing her fumble around or something, cause she placed her hand on my chest to asking if I'm nervous and said that my heartbeat was really fast. I just laughed it off as a joke, but throughout the ride she constantly pats my head and even touched my face a couple of times. So I'm quite confused here, does she like me only in a brother-sister way or what? I think I'm thinking too much here but I just wanted it off my chest. What do you guys think, I would like to hear opinions from the perspective of an outsider.