Yes, there are camping areas around here. Most are closed, and even if they were open (say, for hunters) you would have to register. Most hunting ended on 12/08, I think. And one would have to know the area pretty well to find these camping spots. Not sure how much of a survivalist she is. If she went to one, surely whoever ran it would find it odd that a woman alone would be "camping" in her car, unprepared (no tent, supplies, etc., just her car) and would report it.
Driving around for five days because someone whom she may have planned to meet up with didn't show seems illogical and risky. She would have had to sleep in her car on a back road, which is possible, but pretty dangerous (and scary, I would imagine) for a woman to do, especially alone. She would have had to get food too, and risk being seen. If I were to get away and it couldn't happen that day, I would re-plan.