Why is she doing this?

Theres this girl in my pe class and she just totally came up and started talking to me for no real reason. It was kinda weird since we’d never talked before. Since then, she’s done the same thing on multiple occasions. Also, when im reading a book, she’ll come up and say something like, “what are you reading? Oh, never mind you don’t have to tell me, that was kind of rude sorry.” and then just walk away. Its not that I find this annoying or anything, I just am wondering why she’s doing this. Anybody got any ideas?