Partition of a house

My father-in-law owns a house in Bangalore. We used to live in the upper floor of a two storey house. He had gifted his daughter the lower portion when she married. Five years after we married , our careers took us to USA. My Sister-in-law has been abusing my father-in-law to write a will and give away her share. She thinks that his money is there for her entertainment and enjoyment, for throwing lavish parties, buying expensive dogs etc. She used to demand 50,000 rupees from her father for her monthly expenses! My FIL has always maintained his principle that his wealth is there for a rainy day in the lives of the future generation. he built a nice three storey house in front of the old house. My SIL and her family reside there. Now he has died. My sister-in-law is not a trustworthy person. She thinks that money can buy her status and friends and spends money foolishly. Also, she is emotionally unstable. She has the emotional maturity of a 10 year old. She takes out her frustrations on her pet dogs. I have seen her beat her dogs and throw hot water whenever she was mad at her father over this wealth issue. I am seriously concerned for the health of the people around her when she doesn't get what she wants! Please give me some advise. I want my husband to have as little headache as possible and focus on bereavement, his health, his career and our future. How should we approach this sticky issue and deal with her? My main questions are 1. Will my husband be able to make a joint account and make my Sister-in-law's husband a nominee for her wealth? Our intention is to not let her dwindle away her share of wealth which was my FIL's main worry! 2. How can we divide the house now? Thanks in advance