Would it be better to file a complaint against my aunt because of emotional abuse?

My maternal aunt is second wife of my uncle.My uncle was divorced before. Me and my mother residing in my maternal household because my father used to beat my mother because I was born as a girl child... My aunt used to quarrel with my mother my maternal side families ( grandma ,grandpa, her husband and my uncles 2nd and 3rd child of grandma).She always accused my mother that she had sexual relationship with other guys. If grandmother took my mums side , she always get furious and quarrel more n also beat her child..She also said that my mum had sexual relationship with my uncle who is her actual sibling. Today she had gone above board. She repeated the same words accused my mother again. And as a child of her I can't tolerate those words. i only said who are you to say my mother those things. Have you seen those things? She pushed me hardly. And she started to call everyone in her contacts and said that i had raised hands on her when I have not. She also slut shamed me. And also accused me that i have relation in a bad way that's because i used to go schools or shopping with my uncle. It's not easy to tolerate these things. And if we file a fir in police station we have no idea police will take whose side.. Because my aunt is a manipulator.She already pulled tricks before.She called police before. And accused my maternal family side of domestic violence.She told them that she was the second wife that's why she didn't come with any of the daily necessities that every bride come with basically dowry.And everytime uncle take our side and she told everyone that my uncle beat her everytime because of my mum and grandmother . Honestly my uncle has gone to some extent because who can hear those things against her sister and mother..she have slapped her but not more than 2 times.But she used to say everyday she got beaten. N today also she accused my uncle the same thing when my uncle didn't laid hands on her.She frightened us with the 1st wife's case who also accused us of domestic violence but we have won the case because she had falsely accused us . It is not easy for me to hear all those lies and those slut shaming words.I am just eighteen and I have no idea what to do. N my another uncle's engagement is just 15 days away. She had already planned the publicity stunt.She would call the police and create the mess.although we have voice recordings of today but they are not pretty clear as it's recorded in phone from distance. Can we file a fir against her ?Can my uncle file for divorce and can win the child's custody.For further information the child is only of two years.