Curiosity killed the cat!!!
In the show, Janki wears sindoor and claims to be married. Kajal deserves to know why the father has been orchestrated from the family.
They kept saying "don't ask, don't ask". That is just stupid. At least tell her what happened. All they need to say is that he was drunkard and used to beat his wife and kids. No other stuff/secrets need to be revealed and Kajal's curiosity will be satisfied.
Janki and Raunak have made it a much bigger deal for Kajal than it needs to be. Emotional blackmail does not satisfy anyone's curiosity or stop them from looking for answers.