I had read this as well-- doesn't the timing seem strange? It appears that LE was called and searching pretty quickly, and one would think they would start out in the neighborhood. How much time could the perp have possibly had? It just seems like the murder must have happened pretty quickly.
If the perp is who we think it is, how much time could she (who looks tiny) have had to get Elizabeth out to the woods, kill her, hide the body and get back home? Due to the timing, locations and size of victim and our suspect, I just can't imagine that the perp acted on their own...
And if the account from spacemonkey is indeed correct, then it would seem to me that the murderer would spend more than just a few minutes with the victim...