Raima is like a sister to her so of course she won't believe it. I bet even if she caught them in bed together, Sakshi will probably be like oh, galti se gir gayi bechari Raima. 😆
I honestly do thnk if she knew, she get rid of Raima in a heartbeat. Rajnath might be the image and brand of the Goenka name, but I do believe Sakshi is the real brains behind it. She has this instinct that even he doesn't. However, she's blinded by her so called best friend who's like a sister to her and her believe that Rajnath doesn't have the balls to cheat on her.