Can I claim any share in my mother's assets

Hindu ,my niece who's name in 3 rationcard ,she got m.pharmacy completed for which a flat is still on heavy deposit, she has managed to keep mother under control reluctant to get flat free by paying back money and now she is getting married to her friend keping all debits as it is , is any law that can force her to repay all money spent on studies ?now she is earning good ,she want to grap everything of my father. She is of bad minded and want to help her family .she is always poisoning against me to mother , who is keeping me deprived from everything ,complain to police, mental torched me.