Unmarried couple having a child file IPC 498a and CRPC 125

I m unmarried person, one girl is came in my life forcefully, she was blackmail me if I m not marry her then she will going to attempt a suicide. I took her in my home but not for marriage purpose, but when she came my home she told everyone that we already married but he is not ready to stay with her and she cried which is not true. And my all members also told me to stay with her i have no option. I m ready to stay with her. And now we have a boy children. And she always blackmailing me if I m not giving her money then she will killed our baby. All the time she shouting, fighting, tortured my family. And I decided to separate with her. Since 1year we leave separately. N she filed against us IPC 498a and CRPC 125. CRPC 125 is solved. Can u plz answer me some question. 1. Because of we are not married can she file IPC 498a against us. 2. We r legally and socially married, is divorce needed? 3. CRPC 125 is solve a) can I marry one another girl. Because my mom is too old. b) Is that mean that we are legally separated. 4. If she has a job is it necessary to give maintainance?