Help With this girl plz!?

Ok, so i rele like this girl at my school. I found out that she doesnt have a bf which is good but i talk to her and stuff. I help her if she needs it with science stuff etc and i talk to her about school stuff. Thats where it ends usually all we talk abt is school and nothing ever comes up abt bf gf or like hu stuff. How can i talk to her to get to know her and eventually get a good friendship going and eventually like hu or even ask her out cause she isnt rele being all that "open" to me when we talk and like when i IM her we talk but after we talk for a while it just ends and idk why I dont think she is trying to be rude or anything. What can i do. By the way i found out also taht she is kinda prude in a way how can i get her to open up, hugs hu etc.?