I don't believe she took her own life, is/was pregnant, or is in the custody of someone she knows, or was acquainted with, who was crushing on her and now doesn't know what to do. I don't believe that she encountered a person in distress and reached out, and the tables turned on her and became violent. And I don't believe she had a secret life or hidden deep depression that no one knew about. I've read her Twitter and it's unremarkable in my opinion. Her interactions with others on her social media appears routine and typical to me.
I don't buy into her psych interests or studies or her references to mental health issues/suicide on her Twitter as having anything to do with her own frame of mind. I'm a heavy Twitter user and see a lot of prevention culture's memes and hashtags retweeted and repeated on other people's feeds, and this increases dramatically every time there is a celebrity suicide or a heavily reported child suicide. Nothing she tweeted is alarming or indicative of suicidal ideation, from where I'm sitting. Discussion of "mental health" on social media is also very common because it's a trending topic in our society.
So, sadly, her absence appears to be the result of a crime against her, and while I'd like to be entirely wrong, I believe she's deceased and think she was killed by an opportunist perpetrator/predator somewhere on the jog or some other lone activity that evening that we can't see into.
I also think the FBI presence only indicates (at the very least) LE's belief that she was taken against her will. We had a similar case in my city where a woman disappeared from her office while working late (although there was evidence in the office that someone else had been there) and the FBI was quickly involved. Also, as far as who has jurisdiction and control, recall that in the Delphi case, local LE stated clearly that the investigation was still under its control, and FBI was contributing specialized resources to assist local/county/state agencies.
I've heard so many stories and reports of the timeline and who saw her when and where, I don't really have a clear picture of the geography/distance she might have traveled and where a likely abduction point would be, or what time. But as I understand it, she was known to be alive and walking at 7:30 p.m. on the 18th, and there is apparently a statement by her family that LE knows she was doing homework from the BF's house even later? Someone help me out with that last part.
Also, does it make sense that she was going for dinner as late as 8:30-9:00 or so? And has the mother given any info on a timeline provided by Mollie as to when she expected to arrive for dinner? Not questioning the mother's story, just can't keep up with everything the family has said, and whether or not Mom even had a sense of an arrival time. Sometimes "dinner" doesn't mean sitting down at a particular time, it means 'cooking brats tonight, come on over when you're free, see you then'. Thanks for any clarification!