I almost wonder if there are two separate things going on here, and it's hard to connect them. One is why a little girl would have gone out on a cold, stormy night. Was she lured with the promise of something (could be anything from the promise of a gift or activity from an adult with nefarious motivation to a clandestine meetup with a friend)? Could she have sleepwalked (it's not common but can happen that people leave their homes doing it). Could it be something as simple as she woke up, maybe from a dream, and thought it was much later in the morning than it was and got ready for school, perhaps realizing that it was too early but deciding to walk to school anyway not realizing HOW early, maybe to play on the playground? I know I've woken from a dream thinking, 'oh no, I'm late' and it taking a few minutes to realize that's not the case.
The second is what happened to her after, and while sadly it looks more and more like she was killed not long after she left the house, or at least was taken and died/was killed later. But how that happened, again, could have multiple answers. It could be that someone lured her with malicious intent, either an adult (pedophile?) or another kid (angry about something and wanting to fight or worse). But it also seems like it could have been accidental (hit her with the car and she was seen alive being pulled into it but later passed from injuries? If it was a teen driving, they might have panicked and taken her home instead of to a hospital or to her own house, and once there, she either died or was killed to cover it up). Or, it could have been a crime of opportunity by someone who saw her and took her for the purpose of harming her, a cruel coincidence after she left her house for an unrelated reason.
With our something to connect the POI's family and Asha, it seems more like it could be two separate events that culminated in her death.
MOO, of course, and just thinking out loud to see if anything sounds like it makes sense.