Husband not paying maintenance for mentally ill wife during divorce

My sister who is a mental patient is undergoing mutual divorce which will be finalized next month. We were not aware about the supreme court guidelines on mental illness, links below: http://www.thehindu.com/news/national/man-cant-dump-wife-on-grounds-of-schizophrenia-rules-supreme-court/article5146611.ece http://www.rediff.com/news/report/mental-illness-by-itself-not-enough-for-divorce-hc/20140125.htm We had informed about the illness of my sister before marriage to the groom. After marriage she stayed with her husband for 2-3 months and then she was sent to my brother's place. We reconciled and sent her again but she was sent back again in 3 months. She was not paid expenses during the period. My brother has been paying all her expenses till date. Her husband is only paying 5000/month since the time divorce has been filed. We want to put a stay to divorce and file a case since my brother is not legally responsible for her. Her husband should pay for her accommodation and expenses