How to stop brother's wife from entering house forcefully?

My elder brother got married on Feb 2017 at our native place , and we came back to Delhi(our home) on 19 Feb. She always kept fighting with my brother for no reason and one day in front of her family made false allegations that my brother and elder sister are having illicit relationship. She used to emotionally blackmail my brother that she will suicide and blame us for that and she is woman so we can't do anything. Then we sent a legal notice through a lawyer asking her to apologize for making false allegations on my brother and sis but in return she sent a legal notice and accused my full family with false allegations about my Bro and sis relationship and about my dad also she accused falsely that he tried to be wrong with her, n now she is not even apologetic and trying to forcefully enter our house, how can we let her in, it will be a great mental torture for all of us, just because of a woman, our whole family going through mental torture. Please advise.