I haven't read anyone else's replies to this yet, but I think...
You should not accept her challenge unless they allow it to be free competition. Meaning you can do anything but some obvious things like kicking to the uebos (
), etc.
I've found out on my own that watering down what you know/apply for someone else's satisfaction is a bad thing to do in any type of competition. She says she isn't scared of you guys, yet wants to compete in a 'freestyle' competition with your school. Lowering yourself to their level isn't a good thing to do.