Husnand role when wife is suffeing with STD ?

Hi My brother got married in 2012. He married to a lady who was a widow; she lost her 1st husband and has one baby boy aged around 10 years. My brother got married her with a good intention and adopted the baby boy as his son. Our family felt happy with my brother decision and accepted her as our family member. But From Day one itself (First night) she started talking about “death and suicide”. And later on 3-4 times attempted for suicide for small small issues which normally happens at home . After one week of marriage he came to know that she is suffering with STD (Sexual transmitted disease which she got from her 1st husband) . My brother admitted her in hospital given best treatment by borrowing loan, luckly she don't have HIV . From that day on wards she is repeatedly suffering with STD. Every now and then he takes loan and provides her the better treatment. But she never followed the doctor’s advice or any precautions. Earlier she had family planning operation and now it has been reversed to have kids . But due to her arrogance behavior neither taking care of her health nor her husband's health. Now brother is also suffering with Infections which is making his health conditions up and down. Every time she asks huge amount of money as compensation or scolding for suicide. Sometimes she will not take food for 1 week or more , and says that "let me die like this" ... and she says that i will make your family to beg on the streets . Still My brother took her to the psychiatrist for counseling also , but there is no change in her behavior. Till now my brother never shared this with us. but now a days he is struggling physically and mentally and shared everything with us . Our intention is not get divorce, but will try our best efforts to give them an opportunity to live together.In worst case will go for divorce . If he goes for divorce , is he required to pay money for her ? or any thing like that ? is she having rights on our Huf properties ? We are looking for advice what we need to do.. thanks