The first time Jyoti was asked by Sachin about her siblings, she mentioned that she had 2 siblings rather than 3. At the time, KK had just disowned Sushma, and Jyoti probably didn't want to dishonor her father by being more generous w/ Sushma than even he was, when she was the wronged party.
But just before the wedding, Jyoti had the right instincts when she wanted to fess up about Brij to Pankaj. Kalpana, that genius doctor, stopped her. What exactly was she thinking? And a few days ago, when Jyoti was thinking about revealing Sushma to everybody, KK talked her out of it. Is he some freaking retard? And when Jyoti offered to reveal Sushma as her sister, Sushma threatened to take her life. Nice work, Sushi, encouraging your sister to keep things from your hubby. In fact, not only does Jyoti have to hide this from Pankaj, but now, Sudha has to hide this from Uday. I can guess that Pankaj will be pissed when he finds out, but how about Uday, when he finds out that Sudha was a part of this deception? Or will he only be po'ed @ his bhabi?
At this point, w/ even Pankaj po'ed @ Jyoti, I believe the window for her to tell him anything has closed. I do, however, think that Sudha should tell Uday everything. Since he knows how difficult CM is making things for Jyoti, he'd probably sympathize and not tell his family about this until Jyoti does.
At any rate, this week, Brij re-surfaces. I do hope that Suday are reconciled w/ his family, so that they can get back to family, and let the story move on.