This is the part and hole in the story.
People were trying to entertain it, so as not to jump to conclusions/victim blame, but what with nobody else seeing any such child and nobody reporting missing any such child...
It was possible, or at least in the theoretical realm, that an adult somehow pretended to be a toddler... or that she saw/heard a creeping skunk rustling through tall grass, or something where you only see half of what is going on.
it was also possible that someone took a toddler out in harness as a lure... not at all *probable* IMO; but "vaguely possible"; staying out of sight.
Obviously, some clearer highway cam footage would have removed far more doubt from the off.
But then, when people started leaking part of her cover story on social media, and her cover story contained no further mention of the luring toddler once she got swept off into the bushes by <modsnip>; well, that's problematic.
Somebody that putatively caring and worrying about a stranger infant/toddler... well, for the stranger-toddler not to make an appearance in the alibi story; and for Carlee not to be saying "I kept asking after the baby/they left the baby with me, and the baby's presence was the only thing that was comforting me/keeping me from hysterics", or anything even remotely like that, etc., etc. - well, that's a veritable semaphore of red flags IMO.
The baby disappears from the story/scenario, and all of a sudden she's not the least bit worried about his fate??? ... odd.