Unmaried boy married women

Hi, I am 23 years old and my girl friend is 20 years old. She is from Kolkata and I am from Gujrat, we were in love in engineering days and we loved like 4 years. Unfortunately as her granny passed away by making a stupid promise that my girl friend want to marry her own relative so my girlfriend never got the chance of putting my proposal in front of her parents and she got married. Later after few months she found out that her husband didn't had a job neither well educated neither was taking care of her, he used to beat her and even she was forced to work a lot in her in law home. After few months she started messaging me all her sorrow stories to me and eventually again we fall in love again as she had no one except me in her life. In the mean while she got pregnant as her hubby forced her. Now my question is she is ready to ask for divorce. He even beat her black and blue while she was carrying and he never cared her. Here are the questions 1) With whom she should register the cast is it with any Woman protection cell or in the court? 2) Me n my girlfriend used to chat romantically in whatsapp and in SMS. So if her hubby gives complaint against her telling she used to be in long hours in phone. Will police can trace our messages and arrest us for? 3) How can whatsapp and SMS can be traced and for how long it can be traced? Even if it is traced can it be submitted as the proof? 4) As she is pregnant now what are the complications that will come when she applies for divorce? 5) Her hubby is not ready to give divorce. Now what to do in this situation?