Then,
Proteek can tell her that until now he was thinking her husband left her and that's why he was trying to build a new life for her. But now he has understood she has not only left her loving husband on her own but also has refused him though he has been looking for her for 6 years. He can also tell her she doesn't need to fake as his wife anymore and leave the house.
Sumonto (I hate the fact the child has to know dirty secrets) can tell his mother that he hates her for keeping him away from his daddy and trying to make his daddy go away again.
Milind doesn't need to tell her anything, she herself will know why he will not want to entertain or support her.
Then Prachi can be left alone in the big bad outside world where she has to struggle without anyone, earn her own bread and realize and appreciate the meaning of love, companionship, truth and values of life.
If at all she can establish herself with self respect and without trying to find resort in another man or house, Milind can consider getting her back in his life.