The more I am thinking about it, the more it seems to me that someone intentionally made this case complicated, by introducing some random people. Give or take, I can't imagine that a normal young person with a job, a family of good standing and kids would risk it all by being accessory to the crime. But the presence of such a person, whose only fault might have been sending these text, is very interesting.
It is true that PF might have needed help with cleaning, disposal of the body and tying loose ends.
But am I the only one who is beginning to think that "Idaho trace" might have been an intentional red herring, and while we all are counting the hours to get to ID from CO, someone, way more implicated, might have taken off in a totally opposite direction?
The reason I have this feeling is because the case is becoming oddly complicated, almost farcically so. Here is the case with a very weak motive, an strange alibi, no body, no known mode of death (all we know it was violent), and the suspect who seems to have taken a vow of silence.
(Lastly - if some phones can indeed send preset texts when the phone is switched on, PF could have merely given IN a cellphone, saying mysteriously, "promise not to switch it on before you get home". She may have expected some pleasant surprise, like "I love you" or something equally romantic popping up on the home screen. Who knows?)