I'm very curious if she was spotted on the trail, and if she was, was she headed north or south. I believe I read she was from or staying in New Freedom, which is in Pennsylvania close to the Maryland border. If she wanted to disappear she could have just walked to Maryland from New Freedom and used the Maryland trail. If she was in a state of mind that led to self harm, she probably didn't stay ON the trail. The creek it follows is not deep, there are no large bridges on the trail itself. Plus they'd have found her by now if she was close to the trail.
If she was abducted, I would think from the parking lot would be far more likely than on the trail. ALthough there are many access points. And they've said they don't believe anything criminal. If it was some kind of mix of the two, like needing to have a quiet moment in nature and then some kind of criminal thing occurred, that would be far more difficult to know. Still in the realm of possible though, IMO. If she walked north, she could have done the north part of the trail easily in one day(or been anywhere in York city). Likewise, she could have walked south and been in Maryland in one day. So the search really needs to go further into the woods, and further north and south if they haven't found her. Perhaps they've had other police areas quietly looking? Park rangers keeping an eye out?
I hope for her and her family they solve this.