Husband and In laws are harnessing

My young sister got love marriage(registered) in 2012, after marriage my brother in law took her to the marital home and her in laws started harnessing her like anything, my sister and husband got separated from the ln laws and living separately. But the problem started when his elder brother got married. my bro-in-laws parents brain washed my bro-in-law and he started asking things from us like gold, bike,fridge etc... we started giving one by one to save the relationship with them, now the situation is worst, his parents started comparing all the dowry which their elder brother got and she brain washed my bro-in-law. My sister having 1 year baby and bro-in-law is not even giving house allowances also, he is laying that he is not getting salary, his company is not paying salary etc ... he want to take my sister to parents home,but her parents are insulting my sister like anything, they are abusing also. If husband is not helping his wife then where she will go ? her father in law is Xarmy man, he is saying that we cant file harassment case on him.My bro-in-law also saying that he wont give single rupee for the maintenance. My questions 1) Bro-in-laws is getting around 45k how can my sister can get if she applied for maintenance ? he is getting salary by hand in this case he can say he is not working too, then how to proceed. 2) Since her father in law is the X army man my sister cant file a case against him for the abuse ? 3) she dont want to take divorce for sure, she just want maintenance for her and baby. can she ask for babies education too ? please help us with these questions ?