Geet: Pregnancy ke time par papita khana shayad galat hota hai.
Maan: Pregnancy mein to bade papita khane se mana karte hain.
I think it was very natural. Neither Geet, nor Maan really know for sure. (Geet is after all a 18 year old with nobody to advice her!). Geet says "shayad". Maan thinks of what he has heard the elders talking. Even my reaction when I saw dadi holding papita was "Serials mein dekha hai ki pregnancy mein papita nahin khate" 😛
So, I think it was nicely and naturally portrayed. They are not some experienced elders. But young people trying to do their best.