I'm curious... Did you guys try to have sex on school grounds? Because if that's the case, that alone could be adding another level of stress for her. I would suggest a really relaxing setting with no time constraints. Also, it worries me that you say that you "once again attempted to get her at least willing to try." That says to me that you're pressuring her a little and she might not actually be ready (just likes to talk about it). My suggestion is don't even bring it up, don't try to have sex, just let her call the shots. When she is ready, she'll let you know on her own.