If we look at just that scene independent of everything she has done so far and also what she will do next week (trip promo with Virat), maybe I don't know what to feel about that scene.
Actually if she was neutral to Sai, just be like Mohit, I would have definitely felt bad even if she dug her a hole and jumped into it with her marriage.
However she took many deliberate decisions not only spoiling her own and Samrat's life, but by deliberately siding with Kaku, without thinking of the rational behind it, she actively is trying to harm an 18 year old.
After all this, does she go back and reflect on what she did wrong with Sai, no.
Instead she is probably day dreaming about Virat and thinks of new ways to harm and taunt Sai next day.
She once again came to the correct conclusion after realizing her loneliness and unable to reason with herself on what she is still doing in that house. She asked the right question to Virat today.
His answer tomorrow will give her another chance to leave that house and go back to her parents, continue her own career and move on with her life, but we know that she does not grab that opportunity and instead grabs the shovel to make the hole into a grave.