the whole thing sounds so wierd

are you sure you didn't cut her when driving in the traffic, so she got mad at you?

anyway, find out what exactly she's sueing you first, then think of a strategy.

if she sues you for keying her car, before you got asked "did you do it", ask this question "do you have any proof that I keyed your car, as a matter of fact, my car has been keyd in the same afternoon and also someone took off the wiper". then wait for her to prove, if she could, admit it and apolygize, also explain why you did it. If she can't prove, you can ask "I'm also wondering who keyed my car. did you key my car and take off the wiper because you thought it was me keyed your car?"

better to consult a lawyer regard if you could ask for proof before answer the question "did you do it" from the judge.