[TalnSG]

Absolutely tell her - in person - not an email. One -she should appreciate the effort you make to catch up with her, two - she will appreciate it even more when she realizes that your shyness means the explanation in person was even harder.

At this point if she is actually avoiding you she probably feels embarrassed because she thinks she made the first move on a guy who had no interest in her. You need to clear that up ASAP, before the bad feelings over making a mistake have a chance to sour into dislike.