Procedure for complaining against Husband and In-laws (urgent)

I am writing this in behalf of my Sister who was mentally tortured by her in-laws and her husband living in dubai regarding a few little family issues. It was a day when my sister was not well and they took her to a clinic and in the night she was very much ill that she can't take care her 2 little children who are a 6 month and another a 1.5 year old. In the next morning she got up early while being ill and her father-in-law ordered her food and she made it with this condition. At one point she got frustrated and had shouted loud on her children. Seeing this her sister-in-law who lives with her husband in the same flat said wrong and they had a word fight. After that my sister's husband called up and shouted loud on her wife and asked her to say sorry to her own sister. My sister said sorry, but her sister-in-law created a huge scene out of it and didn't accept her apology. After this whole scene my sister called me and when I came there my sister's husband shouted on phone and asked me take her home as she didn't sorry to her sister(Which my sister already did). Also, there was one guy who was my sister's cousin brother-in-law who assaulted my sister with wrong words and allegations. After this I settled down all the issue for a night and in the morning again my sister asked her father-in-law that she wanted to go her parents home. A call came from her husband asking her not to go untill her relative came and takes her home permanently. She requested and on this point her husband called that guy who was his brother-in-law and asked him to misbehave with her wife by pushing her out of the house. At this I came to my sisters house and had a fight with that guy who misbehaved with me. When I resisted that guy's mother and brother starting beating. After this I longed a complaint against them and my sister's in-laws. I asked security and took my sister home. Its been 2 month but her husband is misbehaving continuously and asking us to take the complaint back and is organizing a sorry note which will signed by my sister and other 2 witnesses that she will not do anything bad again and if she did he will divorce. This was against my sister's will, so she objected and asked to put her conditions too for condition. When they heard that they were not ready and her husband said he will file for divorce. My request is that we need guide to file complaint against him and her in-laws as she was mentally tortured many time and her husband never talked or listened to her points. Also, she is left with 2 children to whom she can't feed and they rely on her husband's income for them. Even if she worked she cannot afford herself and her children. Pls advice what should be done to this case?