For my own reasons, I dont want her to be Zain's sister permanently. She doesnt look younger than Zain and Aliya for me. Also all this evil intentions doesnt go by her. I want this to be some big scheme Mir Khan has played. Maybe make her the fake Barkat who seeing the Abdullah families bonding decides not to destroy them after several attempts at it? Understand Zain and Aliya's relationship and feel guilty and Make her confess and exit the show on a positive note bringing in the real Barkat.
At this point am hoping. Only next week's episode will tell.