What do your instincts tell you about the situation? It seems like you're too afraid she won't react well so you're keeping a lot of distance, but when you two are alone, are there awkward moments where you think she might be thinking what you are? (Sorry if I'm confusing you, lol.) In my experience, both parties are usually too shy to say anything because they're both worried of being rejected, but if you feel she could be interested, try easing into the conversation, like bismarkarek said.
It could be that you just recently started to become attracted to her because she was giving you signals that she's interested in you. You might have missed out on this because you have been trying to keep some distance, but if you try to relax and be yourself around her, you mihgt see things in a different light. Maybe she is becoming curious and you can sense that she might be interested, which is spurring on your feelings as well.
I hope that helps - I know it can be difficult. Good luck.
Tanya in Austria