Okay, so I made up my own list for a MythBuster
Reasons WHY HE would runaway without telling anyone
Mofia/gang/drug lords hunting her down
In so much debt/needing to file bankruptcy
Problem to ashamed to talk about
Afraid someone (an ex maybe) was going to harm her
Fear of going to jail
Reasons why ALL of the above CANNOT be true
reading her SM posts it seems as though she loved her brother and sister a lot. I would think if she stopped home to get the mail or saw her sister at all the week prior she would have told her. She would have said I love you and I always will, you have got to keep this a secret for me, I am going to be okay but I need to hide out for a while, do not tell anyone. I think six weeks in, her sister would have told her parents by now. There is no way she would watch them go through this and not say anything. I don't believe she had any drug problems (she may have had some recreational use but thats not a big deal IMO) big enough to need to hide out or go to rehab. Why leave the car at PTL? Why not just leave it at the condo?
The ONLY reason I could think of that she would run away is to somehow blame/ruin om and omw's life. If she felt she couldn't have OM, the thought of leaving town and making it look like they had something to do with it to "get back" at him is possible. In this scenario, if she went to all the trouble of leaving the car at the landing, she would have added a few more elements to tie OM to the crime. Why not toss your phone, wallet, a few drops of blood in OM's yard on the way out of town?
For there person who asked, yes we have a small airport here, greyhound and train service (within an hour) but I would think LE looked at their cameras already.