Daughter in law filed a false case

In 2016 my brother had a love marriage with a girl he was in live-in relationship for three years. They were college friends and studing in another city, the girl was from. The girl's parents are no more. My father was not in favour of this marriage, still for their adamant wish, got them married by taking loan money. Never took any pany from the girl though. No dowry at all. They continued to stay in another city even after marriage as they said there are more opportunities and the girl is accustomed to her native place weather. My parents didn't say anything and wished them to live happily. But they started ignoring my parents and never helped my parents with the loans my parents took for his studies and marriage. After two years he asked my father to help him financially to set up a hotel buisness as the real estate business he was in going into reccestion. My father helped him again and gave him money. (My brother and his wife both are extravagant and spend without saving much.) After only one year bhai said his business is not doing good and shut it. Then bhabhi planned to go abroad and study hence she spent lakhs of money on this but couldn't get admission. Then mutually they decided to send bhai abroad to earn without asking parents. After bhai went abroad, bhabhi stopped talking to bhai. As bhai had no known in abroad, he didn't get a job and soon he was out of money. One day she came to my parents and asked them to take their grand daughter. But my parents refused it as my parents are old and my father is retired and they are unable to take care of a little granddaughter without her mother or father staying with them. (I live in another city because of my job) Now bhabhi has filed a case against my parents stating my parents didn't help her when my brother has been mistreating her from years of which my parents had no idea. (She did not complained against bhai abroad. I don't know why) My parents received a msg from bhabhi ( threatening us she will now make us pay for how much bhai has troubled her). also received a call from mahila thana after a few days. and had to go to her far native state where she had lodged the complaint, where she insulted my parents and me also (objecting to my personal life that's not related to her). Now bhai is continuously asking for more and more money from us and in the other side bhabhi is harrassing her through this case. My father is old and has the responsibility to marry her two daughters. He is mentally disturbed and He has not much money to spend on this false case. Is this case going worse in next date ? Could police arrest my family without doing any wrong? How can we close this case and save us from future tragedies because of bhai and bhabhi. Suggest us. Help us.