I am so sorry to hear about your cat! This lady is an idiot and you are being FAR to nice. I'd make her life a living hell. How about calling the cops and putting in a complaint of her speeding. Let them know that she hit your cat. They may just set a speed trap to catch her.

As far as using her father as an excuse, horse puckies!! She still should be obeying the rules of the road. Jerk!!