Need an advise which is personal /

My sis in law was having sex chats with one of her ex boyfriend. It came to my notice when she by mistake opened her fb ac on my pc. I did not want to have any problems in thier marriage hence I created a fake account and warned her not to do so. She reported this message in crime cell thinking that i did not have any proof. But I had saved her fb chats with her bf. After that a lot many things came to our notice. I agreed at home that I did it and the complaint was taken back. But at that time we understood lot many things about her. Still my brother for the sake of the kids went ahead with the marriage. After 2 years again my brother found that she was chatting to an online person she met also sending him her photos .Now she is gone to her mothers place and she is done a complaint that we do not let her meet her childrens 2 kids 6years and 3 years. She is again pulling me in this as why was the report taken back and wanted to put me behind the bars. Please advise