✔ 最佳答案
Many people who are shy tend to come off the wrong way, so I must first applaud you for giving this girl the chance ... and taking the time she needs to be able to trust and get comfortable enough with you to open up.
What I would try is beginning conversations with things that are easiest for her to talk about - keep the conversation directed toward her, without being too overwhelming (ask her how her day went, what she's doing over the weekend, and generally easy questions that allow her to answer). Find out what things she's interested in and what you have in common (whether it's a hobby, activity, or a new book or movie).
Reassure her regularly (but again, not too aggressively) that you really like her and want to get to know her better. I think the most important thing with someone who is shy is to give them time before giving up - she could end up to be quite the opposite of shy once she is comfortable with you.