Hit and run

Apologize profusely; fill out any necessary accident reports or insurance paperwork and exchange information; do NOT take responsibility for the action unless you want to make it a foregone conclusion that she will sue you and win (so when you apologize, don't say it was your fault); if the police do show up, politely explain you momentarily lost your head or panicked--you did flee the scene of an accident, so you technically could be arrested, but if after that you are forthright, cooperative, and apologetic, the odds are good you won't be...and that if you are, it will be treated lightly.