divorce

Hello sir, My sister got married in january 2014. Her mother in law has a major influence on her son. 2-3months after marriage she startin harrasing her mentally. She never said anything directly but find ways to taunt her. Her mother in law never let her go out after marriage neither alone nor with her husband and also never took her out. Actually she was not allowed to go out and even her mother in law said to her servants not to do any work of my sister and told her to do herself. After 6months dey sent my sister to her parent's place and her husband said he'll come . But her husband stopped answering her calls. And next day when my parents went to her in laws place and asked the reasons den dey made stupid and foolish complaints of her which makes no sense. For example: she doesnot clean her room.(she never kept her room untidy), she doesnot cook (she always cooked but her mother in law never appreciated her for anything) , her father in law had a complaint from my father that he doesnot drink. Etc etc.. her husband wants separation and all this is happening because of her mother in law. My dad consulted a lawyer he said a new ruling of supreme court says dat v cant file any suit against whole family and can only file suit against dere son and also he cant get arrested. They dont have any reason for throwing my sister out of dere house like this after 7months . We tried many ways to patchup but no response from der side. My sister's husband is not even ready to meet her alone. I'll come straight to the point we want to file suit againt whole family so dat dey get a lesson and never do the same with any other girl.