After Ashwini, Shivani is the only one who truly cares for Sai and also Virat. Anyone who thinks that by ill-treating Sai, they are not hurting Virat are living in their fallacy.
I have loved Shivani on a number of occasions, including the time she actually walked up to PP's first best friend and asked her why she was so upset at her wedding ceremonies. And then the gruh pravesh, the Kaku wanting to hit Sai with danda and of course today.
Even yesterday her, "So aap kya chahati Hain ki Virat poori Zindagi dukhi rahe?" She's the practical and sane one.
It shows that PP might think she has numbers on her side of the team but Sai actually has pure loyalty, the ones who'll stand with her through thick and thin without vested interests