Why does she stare at me?

I'm bi, a girl, and a freshman. So school just started and one day in English, I noticed this girl staring at me. And then we kept glancing at each other throughout the period. This has been going on for the whole week. I just moved here and don't know anyone. I was also here for like a month in 6th grade, then moved back, long story. But I don't think I recognize her from 6th grade. I think she's cute but I want to know what she's thinking or even why she stares at me often. Also, Wednesday, at the pep rally, she's a cheerleader and that group of cheerleaders were facing me at the time and towards the beginning of the pep rally, we caught each other's eye for a second and then she looked away. And then again, towards the end, she was looking the other way and when she turned back she looked directly at me in the crowd, almost as if she was looking for me. She doesn't smile or make any kind of face. She just....looks at me. Why do you think she does that? And no rude comments!!

Thanks in advance.