There r a number of things Saras can do .
1] getting a sample of Durgas food secretly tested .
2] Continuing relentlessly keeping contact with Ranbir and helping him to run from hospital .
3] If Karan no longer is helping her , employing Dev or Hasmukh to do so .
5] Agreeing to take the medicene given to her by doc saying she has fear of injections and throwing them away when no one is looking and preserving her sanity .
6] And deciding firmly NOT to scream and keep saying he is Bhavishya since it is clear by now that her panic goes against her .
7] She can go one step further and apologize to Durga and say she was wrong she has now realised that it is indeed Ranbir . And to make up she shud take responsibility of clearing up her food etc .
These r the tnings Saras can do and shud do .