I think you are being really harsh and a bit quick to jugde her, because what is Purva supposed to do. If your sister's future is at skate, and you know that it would collapse her world, what would you do? Stand back to mind your own buisness and do nothing. That's very selfish. Purva was right to do what she had to do.
I have two younger sisters and I would do anything to secure their life, and future also ensure that their beautiful smile is always there.
I'm new to this and I love all sisters, but right now Askashi doing my head in how can she not realise that is it impossible for her husband to gain load of money in a short time as a delivery boy.