I can't see anything wrong in the descripttion which you have given. If you have shown normal pictures of the girl which she herself has uploaded on the Social Media Platform, then there's nothing wrong in it.
Regarding the Chat messages which you have shared with the guy, you need to be a little more explanatory with them in regards to their content. What was the nature of those messages? Were those chats intimate, did both of you exchange any personal information or was it something she shared with you with a note of trust keeping in mind that you will not show it to any third person?
If the girl is threatening you about the FIR, then its better that you speak to a Legal advisor, since the nature of the chat between you and your Ex- Girlfriend lacks clarity.
Hope this piece of information was helpful to you.