Divorce for woman with kid

Hello, A woman, Roma, has 11 month old kid. Her husband, Sanjeev, is not supportive after marriage. Roma's sister -in-law Poonam interferes a lot in her life. Poonam never allows Sanjeev and Roma to live peacefully. After marriage Sanjeev and Roma had lot of fight over this issue. Sanjeev use to record all fights so that he can use it during divorce. Roma was not aware as she never had bad intentions. During initial days of marriage, Sanjeev used to tease Roma saying that after divorce she can take bed and sofa with her, as joke. Sanjeev started drinking and smoking daily. His brother in law (Poonam's Husband Dillip),also interferes alot. One night Sanjeev and Dillip were having drinks at Roma's home. Dillip told Sanjeev that Roma is going mad. What should be done now? Roma felt bad and she had a fight with Sanjeev on this and abused Dillip and family. Now Sanjeev wants divorce. Roma had a troubled life since marriage. She never had peaceful days with her husband. Her husband before marriage said he is occasional drinker. But now he is full time drinker and smoker. His father had same habits. He never took care of his 11 month old kid. He spends most of his time with his sister Poonam. He gives only 30 mins to 60 mins for wife and kid. Roma wants to save the marriage for kid but Sanjeev is not interested in kid and Roma because he is under influence of his sister Poonam and brother in law Dillip. What should we do now? Please help