Its fine if she calls Virat and he goes to help her out too. She is a human too and feeling alone during that time is scary. However despite having parents, she choose to be with Virat who killed her husband, which makes us hate that she is calling Virat any time.
See she is not responsible for Sai-Virat relationship. It is Virat himself.
He hid things from Sai and problem is that he did not think through. He thinks everything will be fine in 2-3 days. If Sai does not come to know about truth completely now, Shruti and child will be Virat's second family for the rest of his life if Sada never returns.
Only reason Virat will be saved from doing that is because Sai will bring the truth out and most likely give a correct outcome - either leave him so that he can make them the official family or tell him to choose one. Its one thing to give financial security vs emotional support hiding from wife.