RSBM, BBMIt seems like the parents made a few statements about the timeline of her disappearance but they don't give any additional details and have asked for lawyers. I don't even know why the parent's argument was mentioned in the first place because in the context of everything, it doesn't seem relevant. Unless they said that is why the stepfather drove to Michigan the next day or if they're implying that was a possible reason why MC left.
This! Exactly this. How does “we argued the night before” pertain to the missing daughter? That jumped right out at me. Her child is missing for weeks!