Intercourse with mutual consent and without any promise for marriage

A girl proposed me, I rejected. And she wants to be like friends and I said ok and we move like friends. I told her don't place any hope for marriage because I don't want and it won't happen and she also said ok you can marry any one you want. After that We travel like friends and I took her to my home also. After some days we both had an intercourse with mutual consent without any marriage promise. And one day I took her to my home there mother and brother was discussing about my marriage. At that day she asked me Do you want to marry me? I said No I already told you. After that day she went to my brothers home, to my friends and to my mother and revealed everything in between us without knowing me. After 10days she filed a police complaint with the points 1.sexual harrasment 2. False marriage promise And police was saying she was trapped me and I have to go for compromise and she was asking for marriage only and threatening me that it will go for a rape case and you will be suffer. If I say no she wants to go for FIR and legal procedures. I have the WhatsApp chat as a proof that "I said no for marriage and she said ok" Please help me for further steps and actions. Thank you.