I've met a girl in my department at university, and although I wasn't initially interested in her, she would often laugh at my dumbest jokes and flash me unwarranted smiles, so I thought perhaps she might be interested in me. We traveled to a conference together and thus had quite a lot of time to chat and get to know each other. She even agreed to go out to dinner with me one night, and we enjoyed ourselves and discovered that we both like many of the same things, from food to art to music and more. (Several weeks later, we returned to a subject of conversation from that night, and to my surprise, she was able to quote verbatim some of the things I told her over dinner!) I ended up paying for the cab+dinner, and despite my protests, she promised to pay me back.
It took her a long time and a lot of effort to find the cash to pay me back, because she's an international student and the closest branch of her bank is far from our small university town. As a token of gratitude and to express my affection, I decided to do something special for her: I purchased some high-quality looseleaf tea, stitched my own teabags, and gave it to her as a little handmade gift. To my horror, she seemed very disgruntled by the gift. I didn't get a chance to explain why I gave the gift: she took it, smiled, said "thanks I'll try it" and practically ran away. Ever since, she has been extremely awkward around me, averting her gaze, avoiding me every chance she can get, not responding to emails, refusing to initiate conversations with me, and abruptly ending conversations that I try to start with her. She has not mentioned what she thought of the tea or if she even tried it. However, she seems to be on very good terms with the other students in the department.
I'm very concerned that I have somehow offended this girl or made her uncomfortable, and I don't know how to proceed. I feel like I should forget about her, but I'm confused and depressed about how her apparent interest in me has evaporated so quickly. At this point, I'm having trouble deciding whether I should:
Leave her alone and never speak to her again. This is highly undesirable, but maybe she'd be happiest if I vanished from her life.
Apologize. This seems like it would make the situation even more awkward.
Pretend it never happened, and after giving her time and space, continue to interact with her as before, with the intention of one day telling her how I feel about her. I guess this is the ideal scenario for me.
How can I once again be on friendly, talking terms with her, and if possible, have her regain her interest in me?
Background information: I'm Asian American, and she's Eastern European. We're both beginning graduate students.