My mom hit a young girl many years ago(before cell phones had even been thought of) in front of a school many years ago in similar circumstances. The girl just darted out from the sidewalk, headed to the school across the street, and not more than a few feet in front of her. Fortunately, my mom was already slowing down for a red light and was probably only going ~5mph, but as she describes it even though she slammed on the brakes and stopped within a few feet, it was still a few feet too late. The girl was banged up pretty badly, but fortunately did recover fully. She ended up on my mom's hood, which was also probably somewhat better than going under the car.