I know it's much easier said than done but try to remain calm while talking to her. Just ask her questions, like you're interviewing her. Maybe you're in the same class.. ask her about homework, classwork, etc. It's not about WHAT you say, as long as you're talking. A lot of conversations are enjoyable not exactly due to what is being talked about but how it is done. There's a lot of silent cues and non verbal communication that goes during this moment that determines whether we make a connection with the person. I hope you get what I'm talking about. Just talk, even if you have nothing to talk about.