I also think due to hanging herself , she can easily die but if Ash tries to commit suicide she can cut her wrist or eat sleeping pills..so if it is real ash will prefer these two but not hanging..HOpe i made a point here..Now Prem fears seeing this dream and not tells anything to Heer..By that time Harman can find some clue about Sneha not being Ash's dotty..Lets see how Heer will get to know the truth???..Now that is main confusion here