MOO
Consider their regular family life. AF dad, SAHM (I think), 3 kids. Neighbors liked the family, from all reported accounts. A normal family, kids have friends, etc.
Then marital discord over X, SM applies for flight attendant job, wants out of the marriage, wants to go back to Carolina, then opportunity, dad's out of town, SM does what?
What is her motivation for abruptly taking GS somewhere, returning without him? Why not the girl? He saw something he shouldn't have? She's secretly a criminal? It's a stretch imho to say she snapped because the kid got on her nerves (after all the time they've been a family under one roof?) and killed him? Two other kids lived there. That's a Drees built house, easy to hear everything going on everywhere, even in the basement.
Why would she sell him into sex trafficking, as has been suggested? In Colorado Springs? Have also heard the theory she was trying to hurt the mom and dad by taking him and hiding him, to make her feel powerful, to show them.
Where is Occam's Razor in all of this?
MOO