So I keep going back to the beginning -- to her *first* story, that he was a runaway, and to her confidence in her eventual vindication -- before any of the proverbial merde started hitting the fan. It seems to me that whatever happened would have to had to have been *designed* to be optically consistent, at least in terms of the way she *expected* things to play out, with her first narrative.
And it also seems to me that her ideal scenario must have been something that would make *everyone* see how wonderful she was -- including her dh -- and there's simply no way *any* parent would still think you were wonderful upon finding out that their child had died while left in your care, even accidentally.
So perhaps there *was* no disposing of a body. Perhaps the goal was to have staged a runaway, and then for her to subsequently have found the little transgressor and emerged heroically, cementing her reputation (not only in the community but also in the eyes of her husband) as the beleaguered but tolerant and deeply loving stepmom..
But then -- how could this have happened without the boy having been able to refute the narrative? Maybe this is where the questions re the meds play in. What if she left a mildly injured and perhaps slightly overdosed kiddo, who had (predictably) fallen asleep in the car, in a place from which she expected him to eventually emerge safe and sound, and of his own volition..
But then, he doesn't come back.
And on top of that, she then perhaps goes hunting, and he doesn't even seem to be anywhere near where she had expected to find him. Maybe full panic mode ensues, and she's actually kind of as confused as everybody else ... except that she no longer really has the luxury of being able to tell the truth (and there is nothing like lying to addle the brain). And maybe this also explains why her story is constantly in flux -- because it's changing along w her best guessses as to what's actually transpired.
And *then* at some point it would perhaps have occurred to her that there may still be some traces of some minor (if still egregious) harm done to the boy -- which now turns into a major issue rather than an minor one, and maybe what she is trying to hide with all the vehicle sleight-of-hand is not evidence of a felony, but rather evidence of having been a catastrophically crummy stepmother.
And finally, her vision of having emerged from this ill-conceived charade as champion of the day has turned to absolute panic. And to me, that state of mind could explain the incoherence of all her communications to date …
Okay, just a thought …