Good analysis Janki. Even I felt bad for Ashwini today. She is going to feel very bad when she comes to know that Sai was only acting in front of Kaku and the family. Yesterday's Ashwini - Sai scene was very nice. Sai had really felt that she had made a mistake and apologized to Ashwini. Hope Ashwini does not think that Sai was acting and fooling her also.
Sai is trusting that Virat will support her if he knows the truth. Maybe she knows it would be difficult to convince him but she is not giving much thought to it. Her goal is only Devkit marriage now. I don't think she expects Virat to throw her out of the house. But ultimately when this happens both will suffer and maybe realize the depth of the feelings they have for each other.
Yes you are right. Ashwini will most likely feel Sai was lying to her about being apologetic as well without knowing that it was later that Sai learnt the truth... Ashwini will really lose her cool and have a heart break I think. Also because it is true that getting Devyani to run away is a big , big error in the eyes of Ashwini too -- she is not going to be okay with it.
Sai definitely thinks Virat will side with her and is not even thinking of the consequences because she is too occupied with the mission at hand -- but I am not sure if she's thinking enough to at least gather evidence to support her story... we will know