Also watched the episode again...Raj had mentioned to Simran that Sid's life is in danger. So I think Roshni too had figured out that her Sid is in danger. Also, when DD was telling her that she loves Sid and would fight villians for him. I feel it hinted to it as well. She is fighting for him. She knows he will but she too wants to for a time do something for him. She knows Sid fights her battles for her and ends up in trouble. So she takes it upon herself to do something. Her being in trouble will force Sid to do something. Or else he might be able to prove anything. Now he will as JT. I think Sid will either overhear Roshni or Roshni will share with JT, which will expose that Roshni is faking and that too to protect Sid n her family. But I hope once he knows the truth about her faking (if she is) he too shares that he is not JT but her Sid. If both know each others plan, I think it will be connected as one big plan to expose Bansi, Shabnam, and Kunal. All will be done for. So much drama and suspense.