Cousin suffering from domestic violence from her father and step mom

My maternal uncle has a daughter from first marriage. His first wife died and then he married another women. His second wife is very abusive towards the daughter and literally doing domestic violence. Her father knows everything and abuses his wife, but does nothing to stop this. He is a businessman and very money minded person and cares about nothing. I wanna know if there is any law to protect my cousin or apply for official custody of her. My mother is ready for her custody. She is 8 years old (Female).