MOO...There was a field trip scheduled for the morning of the 19th, and most staff would ride on a bus with the children. I am not aware if MT’s brother is employed or what his schedule may be...but I know that personally, if I were to be gone all day where I wouldn’t be at my usual place of employment and I shared a car with a sibling, I would let them use the car for the day. Assuming they had to work of course. And I would probably carpool with someone who lived close. I think it is extremely possible that she had an arrangement with someone for a ride the next morning which is why she wasn’t concerned with picking up the car. This doesn’t mean it’s someone that works at the same place, but MAYBE someone with a similar schedule who works in or near her place of employment. This could be a reason for contact initially, and then something happened. If I were LE, I would look at someone who fits that bill. It’s worth a shot.