Mother living with me,giving pension to sister?

I am sure you are having a tough life with an aged and dependent mother and a Psychiatric patient for a wife. You mom should realize this and pay something to you for her upkeep. Sisters tend to be selfish in India and demand their share of whatever money she gets. Explain everything to her gently and the hardships you you are facing because of insufficient finances and too many dependents who require special care. If she realizes your problem then you can stop her from being abusive and also share her pension with you. Otherwise, you have to take the hard decision of putting her in an old age home. She can pay them from her pension. Let us just hope that good sense prevails in her and she changes for the good. Anyway, it is for you to decide.