Schizophrenia before marriage

1.my brother is married in the month of 25/04/2016, it was arranged marriage 2.My brother had schizophrenia before marriage which we told to girl parents before marriage but we don't have proof 3.girl is currently living with us 3. now we thinks girl may claim for divorce,they are greedy family asking my dad for rs.2 lakh for there work and they may also did recording of all calls before and after marriage 4.now the thing is can the girl claim property of my mother or father as my brother don't have any property on his name,my dad told them that my brother is working with him and its a family business 5.house is owned by my mom on her name and she bought on 2003,2 plots owned by her which she bought on 2006 6.my dad owned a plot which he bought on 2011 7.can she claim from any of these property as my dad told before marriage that my brother is working with him on his business 8.what other thing can girl claim as we now they are greedy family and wants to take max. benefits 9.my brother don't have a single asset on his name he only owns a saving bank account