First, I would have made sure that she knows you’re not going just for her by saying something like “not sure i can make it this saturday. but maybe another time.” Then I would go and pay absolutely no attention to her whatsoever. Say hello at the beginning. Say goodbye at the end. And ignore her completely throughout the event. Flirt with other girls. Talk to all the guys. Make sure she’s aware of your presence, but don’t interact with her unless she initiates the conversation. Even if she does, you should be the one to eventually break it off. Don’t spend too much time talking to her. Flirt a little and move on to other people. Right now, it’s very important to establish that you’re too cool to 1) feel rejected over what happened, and 2) you’re not going to chase her. After some time passes, you can start paying more attention to her, but never more than she’s paying to you.
–Lee