First of all the biggest shock for me is that Rosh actually revealed her and Niks true identity to Shivani. How could she do that because she knows that Shivani is not someone who could keep a secret if her life was in danger.
Second she got to see the footage of Niks buying the medicine. Gauri being the smart one linked Shivani and Niks and Rosh knew she had to choose between them to save. Luckily Niks made it easy for her however tomorrow how does she manage to save herself will be interesting.