A possible storyline could be that Sherlock is initially clueless about how to take care of a baby. He reads every parenting book he can find and tries to apply scientific methods to baby - care. Meanwhile, the baby seems to have an uncanny ability to sense when Sherlock is on to a big clue in a case. As the baby grows, Sherlock discovers that the child has a brilliant mind like his own and starts to train the baby in deductive reasoning, all while still dealing with the normal challenges of raising a child.
A possible storyline is that Mal's baby has a special mark or ability that is prophesied in an old legend. This causes all sorts of characters, both good and bad, to be interested in the baby. Mal then has to form alliances and fight battles to keep her baby safe. Another storyline could be that the baby is half - human and half - something else (like a fairy or a vampire from other Descendants realms), and Mal has to deal with the discrimination and confusion that comes with that.
Well, in Naruto fanfiction, if there's a neglected baby, it might be that the baby is the offspring of a missing - nin. The village, fearing the baby could grow up to be like its parent, neglects it. Maybe the baby has a chakra nature that is considered 'cursed' in the Naruto world, like some form of dark chakra. As a result, the people around avoid the baby, leaving it to fend for itself in a cruel environment.
A storyline could involve the baby getting lost in a magical world. Arthur and Selenia then have to embark on a quest to find their baby. Along the way, they meet various interesting characters who either help or hinder their search. This would add an element of adventure to the fanfiction. It could also show how their love for their baby drives them to overcome all obstacles in their path.
One possible storyline could be that Sonic and Amy face challenges in raising their baby while still dealing with their heroic duties. For example, they might have to protect their baby from Dr. Eggman who sees the child as a potential weapon or leverage.
One possible storyline could be that the baby fox is lost in Zootopia and has to find its way home while encountering different characters who either help or hinder it. For example, it might meet Judy Hopps who takes it under her wing for a while.
Perhaps a storyline where the baby is raised in secrecy. Hawkeye and Black Widow are constantly on the run to keep the baby safe from their enemies. The baby grows up learning survival skills from them. And as the baby gets older, it starts to show signs of wanting to be part of the superhero world, despite the risks. It could also involve the baby having to face some internal conflict, being half - Hawkeye and half - Black Widow in terms of abilities and personality.
One possible storyline could be Ana's journey of grief and self - discovery after losing the baby. She might struggle with her relationship with Christian as they both deal with this loss in different ways.
One possible storyline could be Minato's struggle to find a cure for Naruto's sickness. He might search through all the hidden jutsu in Konoha, asking for help from the elders and the medical ninjas. Another could be Minato's emotional journey as he takes care of his sick baby. He'd be filled with worry, but also determination to see Naruto healthy. For example, he could sacrifice his own sleep to stay by Naruto's side, constantly monitoring his condition.
One possible storyline could be the challenges they face as new parents. Maybe they struggle with finding a balance between their work and taking care of the baby. Another could be how their relationship changes with the new addition to the family. They might have different parenting styles that they need to work through.
One possible storyline could be about the moral and emotional turmoil that Faith goes through. She would have to deal with the unexpected pregnancy and the fact that the baby is related to Buffy in some way. Another could be how the Buffy - related characters react to this situation, like Willow trying to help with magic or Giles being his usual wise self in giving advice.