If someone hurt you badly and is the reason for a lot of pain in your life...it is normal that you wish the person to be unhappy...specially if you feel helpless...you want to see justice be done...you want proof that God is here and gave you justice. Knowing that the person who did you wrong may be punish when he dies is not enough...you need to see the person being punish weil alive...feeling regret and remorse and asking for forgiveness from the bottom of his heart...then you are able to start forgiving the person...but you never forget what he has done.
One thing is wishing someone to be unhappy and one thing is cursing someone and there wife (she cursed Supriya)...that is not ok.
Now when she meet Naku and Dutta and after she realizing that Dutta remember what he has done and that he feel remorse and regret...if she still wish the baby dead or keep cursing Dutta and Naku...she does not have a clean heart.
I know...that you do not know how you will react before you are in that situation...nothing more painful can be to see your child die...but nothing more painful can be to know that your cursing resolved in a Childs dead.
The lady need peace too...I think she need to forgive to be able to feel some peace.