After having participated in the official search over the weekend, I was fairly confident that if she was somewhere in the search area she would have been found. I have since heard that 90% of the city has been covered. I don't think the search coverage in the surrounding county is anywhere near as complete. Just yesterday as I was driving to work I remembered that a friend owns 5 acres just a couple of miles west from the apartment complex, and that there is a small barn deep in the woods on the property, which is otherwise undeveloped and unused. As soon as I remembered this I had to check it out.
She wasn't there, and there were no signs of any recent activity on the property -- foot prints, tire tracks, recent trash -- but when I subsequently contacted my friend for belated permission, she said she hadn't thought to check the barn. So I'm sure that there are many, many places in the county where she could be that haven't been searched.
It didn't occur to me until later that if Hannah was there when I was checking it out, alone, then JM might have been there too. In which case I probably wouldn't be writing this.