In Diya Aur Baati Hum, looks like Sandhya (Deepika Singh) is hiding something from Sooraj (Anas Rashid) and Bhabho. First Sandhya hides from everyone saying she couldn't go to Scotland. Secondly, she doesn't reveal anyone why she requested to wear salwar kameez instead of sari.
Also, when Sooraj and Sandhya go to market, Ankur sees Sandhya struggling with heavy luggage. Sooraj would have left her alone to get something. Ankur starts scolding seeing Sandhya alone and then bash Sooraj, who joins later, for not taking proper care of Sandhya. When Ankur try and say something regarding Sandhya's health, she stops him not to say. Sooraj looks suspicious but still doesn't ask Sandhya anything, instead says that he will take care of her.
When Sooraj met Sandhya in park, he asks her if she didn't go to Scotland. She avoids the question and asks him to take her home.
At home, when Meenakshi taunts her and asks her why she hasn't gone to Scotland, Sandhya lies by saying she couldn't pass some entrance exam and so she wasn't allowed. Meenakshi doesn't believe this. Everyone at home too ask the same, but she avoids the question.
When Bhabho asks her to wear sari for pooja, she comes with salwar kameez. When Bhabho asks to change, Sandhya asks Bhabho's permission for wearing salwar kameez at home. This surprises everyone, though she accepts Sandhya's request.
Ankur's family visit Sandhya's place, where Ankur's daughter would hug Sandhya tightly. Seems like Sandhya had some stomach pain when the kid hugged, and Ankur looks worried.
In Sandhya's room, Sooraj overhears Ankur-Sandhya's conversation, where Ankur would say he is upset with Sandhya and not Sooraj. Sooraj asks why is Ankur upset with her!
Looks like Ankur is upset that Sandhya didn't look into her career and came back to Raati family. Or he would be upset that Sandhya hasn't told that she had donated her kidney to Bhabho!
We assume that when Sandhya came to see Raati family in Burkha, she would have got to know about Bhabho's health and donates the kidney.