I'm not entirely sure specifically what 'nalu pregnant lemon fanfic' is about as it could be a very niche or even an original creation within a particular fan community. It might involve a story about a character named Nalu who is pregnant, and perhaps the 'lemon' could refer to some sort of citrus - themed element in the story, or in some fanfic contexts, 'lemon' can be a code for something more mature, but without more context it's hard to say for sure.
Well, 'nalu' could be the names of characters from a certain fandom. 'Pregnant' indicates a pregnancy storyline. But 'lemon' is a bit tricky. In fanfic lingo, it sometimes means something racy or adult - related, but it could also just be a random or symbolic element. Maybe it's a fan - created story where Nalu is expecting and the lemon has some special significance within the fictional world of the story, like a magic lemon or something.
The term 'nalu pregnant lemon fanfic' is rather ambiguous. 'Nalu' might be the main characters. The 'pregnant' part sets the plot in a direction of a pregnancy story. Regarding 'lemon', if we assume it's not related to adult content, it could be an object, a place, or even a symbol in the fanfic. For example, it could be that a lemon tree in the story is significant to the pregnant Nalu, perhaps it has healing properties or is a family heirloom that plays an important role in the story as Nalu goes through the pregnancy journey.