Divorce

Sir, my sister got married a central govt. employee, blessed by a son age 15v years. my sister is living separately with his son at our home, as her husband is harassing physically & mentally since last 12 years. Her husband is paying maintenance through court. My sister filed a 498 case against him in Addl. Civil Judge court, Palakollu, West godavari AP and it was dismissed 5 years back. Her husbsnd filed a divorce case in district family court eluru, west godavari, AP in 2016 December. My sister said the court that she will be ready to live with him. But court has granted divorce with out considering he argument and request last week (judgement order yet to be received). Now our advocates is saying to go for appeal in the High court of AP. Since, divorce granted unilaterally, is there any chances to get stay and dissolve the judgement in High Court? Whether her son is having right to get property of his father? Whether my sister can get maintenance in case divorce confirmed in High court also? Kindly advise