I guess this is yet to be confirmed. I heard this wasn't shown in the episode yet. I don't know since I haven't watched the epi. This is what I saw on the forum
Hey there, I saw the episodes, unfortunately. They showed Diljeet claiming that he had been abandoned in Gurudwara as a baby. Even though she was born and raised in Panesar, Amanpreet's mother became tense whenever Panesar was brought up and was unwilling to visit the place. There doesn't seem to be any other explanation for her fear. However, it may be one of those things that writers just forget about.