what they would do is look at you alot, but when you look back to face them, they will pretend to look at something else or will quickly look away.
hey how about check out this page? it has all the things you should pay attention to in a shy girl. i read it and its basically almost all true! haha. heres the link
http://www.wikihow.com/Know-if-a-Shy-Girl-Likes-You-at-School