Regarding Sister case

My Sister first husband put 3 petition in court. My Sister got married with One of guy and they both stay with their life almost 9 Year without child . Child not born because of first Husband has some problem and even his not ready to take treatment from Doctor. So my sister decide to separate but his not ready to sign 100 Stamp Paper but he verbally told my father that you can made second wending but my father wait till 2 year but no reply from first husband later my sister marry ( But no proof of second marry ) and later 1 husband know that his born one child from Second husband and now he put Petition in court . 1. Divorce Petition under Adultery on My Sister 2. Adultery case on my Sister husband ( Second Husband ) 3. My entire Family under – 494 My Sister & under 107 - Myself , Father , Mother , Second Husband. With the help of RTI he got child birth copy from Munipal corporation. So what is your suggestion from our end still we not file any case but now I am going to file property case 50% amount because my Sister name is mention in Index 2 in property paper and I have Xerox copy please let me know your expert view on this. Thanks