Need Divorse from husband

Hi I am writing behalf of my sister. We are from Bihar. and My sister got married in Nov 12 in New Delhi. At the start of marriage husband was behaving good to her. But her mother in law was not good from the start. At the start she is forcing my sister to do some job, even daily they are giving mental tension to her and after some time even husband also started to torture her to do job. and saying that all your degree are fake that's why you are not going for job. Even if for 1 hour she is taking rest, then mother in law started taunting.After some time her mother in law started saying that if you will not get pregnant we will do another marriage of my son. but after some time she got pregnant but somehow it got miscarriage. Again now due to pressure from mother in law and husband she got pregnant and due to not proper medical treatment after 8 months child cannot survive in hospital. and now the drama started in hospital also everyone started mentally harass my sister and even blaming her for everything happened and now situation is that husband was coming daily after drinking wine in hospital. and harassing my sister. and one day in the situation when she delivers 8 month dead child. and in that time when she needs lot of support and care. Her husband used to slap in front of all the public in hospital. When she was not able to bear the cruelty, she immediately somehow called us and we went next day and we took her to our home with the help of family.Lots of things also happened in the meantime that's all can't be explain in this short paragraph. As they were very greedy and cruel and also we give big dowry to him she filed 498A against husband and his family. But now sister want divorce from husband and take all the dowry which we have given at the time of marriage.Is there any way we can get all these settled peacefully and quickly? Please advice.