Some MOO "if-then" theories to muddle over:
Beginning from the house, using Jennifer's map(
Possible Eye Witness Sightings of MT - Google My Maps):
If she was abducted from the house(map pin 1), which was undisturbed according to her BF, she would have probably still been outside of it, and could have been taken then. Then that means the two witnesses who think they saw her(map pin 2,3) were mistaken either about the person, day, time, etc. That seems unlikely, since two separate people seeing the same person is pretty much solid.
If she ran her usual route, and made it to the next sighting, this would bring up to the point where her mom gets a text about dinner. Then *something unknown happens* right at this junction(probably pin of the funeral home sighting on the map). There appears to be a home robbed in close vicinity reported at that moment as well. She could have been headed to her mom's for dinner yet at this time. If she was, then we'd need to know the route taken to get there, and we don't have that. So if this is the point where *something weird happens*, it's something like someone taking her away(to a place out of the town, hence the fitbit ping at the farm(pins 9 and 10 on map). I don't see the last time her devices pinged reported anywhere.
We know she did not go to her mother's for dinner. Her brother and mother say she was *doing homework on her computer* but we still don't know if it was a laptop or desk top. If it was a laptop, then she could have taken it with her and been doing homework somewhere else. If it's a desktop, then the time stamp should show when she was at home. We don't have that piece of info yet.
If the next witness did actually see her, and not someone else going by, then we have her talking on her phone, which means she may have stopped running to answer a call. We don't know if it was Mollie, and the police have not confirmed if there was a phone call made from her phone at that time.
If the last person to see her really did see her, and she was just jogging as usual, we have her heading towards her house. If the person who saw her walking and talking on her phone is correct, then this could mean she a. Was jogging her usual route. b. Got a phone call and someone asked her to meet/stop by/or they would stop by. C. She heads back in the direction of the house to change/get her basic stuff. D. *something totally unusual happens at this point* E. Nothing more is heard from her until the BF opens a Snapchat which shows her indoors.
He says he doesn't remember what the caption said, but if it said something like, OMG help, then he would have probably remembered that. Ditto if it was some sort of language she shares with him like a code word if she's in trouble. So, it either was a casual shot with a regular "how's it going" caption, or it was an attempt to get help. The BF has said they were texting back and forth as usual that night. So during all of the possible scenarios above, she was texting while all of the timeline was happening.
So that leaves this text/snapchat/calling. If it was actually Mollie doing the posting, then something weird happened right in the middle of it suddenly.
But if someone had her somewhere she did not want to stay in, whomever that may be, it could have been that person texting/snapchatting/captioning.
As an aside, I am going to go with the scenario that her brother dropped her off at the BF's house when he said he did, which would begin the timeline right before pin 1 on the map.