Ilness is fake di. She is threatening rachit. If pillu is really ill rachit cannot be or won't be blamed for it. Kallu then need not pretend to be rachit wife she can be free is the only use. But rachit using his money and muscle power has kuch proofs and things I believe so he won't loose anything if moksh is really ill and if he is sampu also won't lose anything
If moksh is Ill there is nothing for the duo to worry about beacuse ultimately though reluctant kalma would succumbs to their demands.
But if pillu is not kalma won't wait for anything both rachit and sampu ka nuksan they will be jailed thats it
Sampu wanted to say illness is fake why I think so because according to her she is not doing all this beacuse he loves malhar and moksh all she wants is money. If malhar is moving to remote village she doesn't prefer to stay with him she would rather expose rachit and herself and stay comfortable wherever she is. She is threatening him that if she doesn't get the comfort she wants bhad Mei Gaya their plan thatsall.