Okay, so if she was harmed by a person known to her, they more likely than not would have known that she was not due to arrive back in Vegas for MANY hours. So this begs the question (again) why would that person bother texting anyone. Even if she never sent a text to anyone, they probably would have thought, "Oh, her phone died." or "She didn't remember to text and then they told the passengers to turn off their phones." etc etc. They wouldn't even worry until she never got off the plane in Vegas. By that time it would be 11pm. That would be 1am back in VA and the perp would have had basically an eternity to hide evidence, as opposed to tossing some of it alongside a road where it was bound to be found.
(My questions are not directed to you in particular, ClaireNC, I'm just jumping off of your post.)
moo