Being a person who was never great at asking girls out in high school and even worse at picking up on hints, I have since learned that many girls floated hints my way and I was just too dense to figure it out. Based on what they've told me about their hinting, it sounds like this girl is definitely dropping a few your way.

The best thing I can think to do is just suck it up and ask. That's all you can do. Catch her some time when she's alone (less chance of embarrassment) and just walk up to her. Don't ask about going out on a date. Just say something simple like, "I was wondering if you want to go get some coffee after school" or the like. If she says yes, use this as an opportunity to talk and get to know her. And make it about her. You obviously know a few things about her. Use those as conversation starters.

All you can do is ask and all she can do is say no. At best, she'll say yes. You won't know until you try and you'll regret it forever afterwards if you do not.

Good luck my young Padawan.