I just want to to analyse this character Ishwari.. She is a mother one of her kind. She lost her husband after 10yrs of marriage. She has 1 son n 3 daughters. She struggled a lot to bring food n give shelter to her child. She is a very strong lady. But she loves her son more than hwr daughters. I think its because her son understand her more n give support. Ishwari made Dev understand that he is the man of the family in the age of 8. She put all the responsibility on him as she knew he is more intelligent. If she gave him good education he will become her "shahara". Again Dev saw from childhood that his mother is an all-round. She can do anything to make him happy. So started taking his mother as God. So he never dare to ask her a question.
But daughters will get married,thats why Ishwari started ignoring them. Thats the result she got a daughter like Neha. But other 2 sisters never seen that side of sacrifice. As per all the flash back what i understood she needs Dev for herself. That is reason whenever she saw a girl with Dev she become insecure. May be it saloni or Sona.
When she first came to know about Dev-Sona relationship she was not happy. But she wants to show her Godly image to Dev,thats why she was happy in fron of him. But when Dev saw her a God in death bed. He took that impusive decision of break up. Then Ishwari noticed her son is going away from her. She decided to bring Sona back to his life so that she could get her son back.
Even after marriage she wants to control his son's life by doing false sacrifice agree to Bengali marriage, nonveg issue, or mudekhai drama. She does not want any change in her n her son life. She doesn't want to let Sona know their past. She doesn't want Sona to advice Dev on office matter,or in personal matter. In short she brought back Sona to Dev's life but treat her as a toy.
But in this BDay situation she also wanted to do the same by keeping Sona away from the preparation. But when she saw Sona's understanding may shake her position of God. She was just shaken doesn't know how to react. Her every dialogue in the last seen has sime meaning. "Yeh party kya hui sab saman idhar udhar ho gaya hai. Kal pura din lagega usse thik karne keliye."
"Konsa cheez kahan rakhni hai mujhse behtar koun jaan sakta hai"
She wanted to show she was guilty, when she was insecure.
Really CV did a great job to show such a character n Supriyaji just nailed it...
Its a very long analysis..thanks for reading...