As you may know from other files found in the games inner workings. You can find a menu that shows that the game was originally going to be seven acts.
Based on information from several sources including the KQ7:The Authorized Guide, and King’s Quest Companion, 4th edition, it seems that there was apparently going to be another Valanice chapter in which you may have had more interactivity with the stranger. Scenes that run on their own in the finished game.
This would suggest that chapter 7 would probably been primarily Rosella chapter finishing the game, or possibly chapter 6 may have been alternating back and forth playing both characters parts. Although that never came to be.
But its not entirely clear.