If my niece filed a false police report against my family, what can we do to ensure this never happens again and that she is held liable?

My 30 years old niece filed a false police report against my family. The police spoke with her and told her never to contact us via any form ever again after speaking with our family and also reported her to DCFS due to her instability and having 3 young children. The allegation has been proven false and I have plenty of proof. She accused me of not contacting the police after my 14 year old daughter was raped 3 weeks ago which never happened. My daughter was interrogated by the police and released after they spoke with her and deemed my niece mentally unstable after speaking with her, which has also been proven. My daughter is so upset by this and rightly so. She is also afraid of what she will do. We have no records of any kind .We are heavily involved with our church and our community. This has devastated our entire family. My daughter is in 8th grade she does not deserve this. She has an extensive criminal record for harassment and domestic violence which many of these were from her husband. She is now contacting my friends and my daughters via social media and of course they are not responding. She is very unstable and capable of anything.