The one who is the root cause of all the mess. Yes, it is Ishwari. She is suffering for the last 7 years and more. But she is not realising and so she is blaming Sona for her suffering. So her suffering will continue.
I feel sorry for her but also annoyed.
Next it is Dev who is suffering but he is trying to cover it up by acting brash. He has developed an outer personality which looks hard but inside he is still the vulnerable Dev. He tries to fill the emptiness by playing with golu, by being upfront, by revolting. I think Ishwari senses his pain but she cant do anything until and unless she acknowledges where she went wrong.
Sona is not suffering because she is not guilty. And she moved on and her loving family is also responsible for their supportive role in her life.
Suhana will make them to loosen up from their rigid stances.