Here's the problem, without information, we can come up with all kinds of ways someone else MIGHT have done this, but we cannot make any truly educated guesses. On any given day, a person could grab someone and speed off with them, a child could voluntarily go with someone they considered a friend, a parent could kill a child and hide the body (or not), a kid could run away by themselves, or with a friend. But with only a path she walked (I have discovered she walked the street route as far as her parents and grandmother knew), some sightings of someone who looked like her walking in the drizzle with a black hoodie on (how can you recognize that, unless there is a distinguishing design on the hoodie or the pants she was wearing), and the information that she did not arrive at school on a day when she had valentines for her friends and was supposed to buy a lamb she was excited about, I see no way to connect her with anyone, except the last person to see her face to face.
I DON'T see this as a standard runaway, unless there is something else we don't know (which is a lot).
