How much will my stuff shift when pulling a TT?

If its loose, it will move! or fall off, or turn over! Whenever we leave on a new trip, the DW stands in the aisle and hangs on to something until we get around the first few turns and hills in our neighborhood. After everything as relocated to its new position, then she can sit down and be comfortable knowing that most everything is wherever it will stay for the rest of the trip.