Well, in the original story, they are both male and in a same - sex relationship. In fanfiction, it's often about exploring alternative universes or magical means. Maybe a powerful magic spell gone wrong or right in some fan - created universe allowed for them to have a baby in some really out - there and creative interpretations.
In the realm of fanfiction, the idea of Hermione being Sirius and Remus' daughter might stem from a desire to explore different family dynamics. It could start with a time - traveling incident where the past is altered. Sirius and Remus might have found a way to ensure Hermione's existence in a different timeline. This would completely change the relationships in the Harry Potter universe and open up new storylines for the author to explore, like how Hermione would grow up with two very different fathers, one a werewolf and the other an escaped convict in the eyes of the wizarding world.
Well, in a fanfiction, anything can be made possible. Maybe it could be through some sort of magic gone awry. For example, a spell that was meant to protect Hermione's real parents ended up warping reality and making her seem like Remus and Sirius' daughter. Another idea could be that some dark wizard had a plan to manipulate their genes or magical essence in some way to create this new family connection.
Common themes often include the challenges of parenting. Remus and Sirius, given their own backstories, might have concerns about passing on their 'wolfish' or 'troubled' traits to the baby. Also, themes of love and protection are prevalent. They would do anything to keep their baby safe in a world that might not be fully accepting of their relationship or the existence of their baby. And there's usually a theme of building a new kind of family, different from the traditional ones in the wizarding world.
In fanfiction, Sirius and Remus could fight over Hermione because of their different relationships with Harry. Since Hermione is Harry's close friend, Sirius might think that he should have more influence over Hermione to help Harry better, as he is Harry's godfather. On the other hand, Remus, being Harry's former teacher and friend, also feels a sense of responsibility towards Hermione because of her connection to Harry. This clash of responsibilities and their own personal feelings for Hermione can spark a fight.
Well, in fanfiction, anything can be possible. Maybe it could be a result of some time - turning magic gone wrong. Or perhaps there was a secret relationship between Sirius and Hermione's mother that was never revealed in the original story. It's all about creative interpretations in fanfiction.
In fanfiction, it's often about bending the rules of the original universe. It could be possible through magical means that weren't explored in the original books. Maybe a powerful spell went wrong and created an unexpected bond between Hermione and Severus, leading to the birth of a baby. Another idea could be that in an alternate reality, their relationship developed in a completely different way, allowing for such a situation to occur.
One possible plotline could be that Sirius and Remus initially struggle with their inappropriate feelings towards Harry. They might then realize it's wrong and instead focus on their roles as his protectors. They could channel their strong emotions into teaching Harry more about his parents and the wizarding world, turning a potentially dark concept into a positive mentoring relationship.
Maybe in the fanfiction, Harry would develop a different set of skills. Since Sirius is brave and a bit of a rebel, Harry might learn some more unorthodox ways of using magic. And with Remus being very knowledgeable, Harry could be well - versed in magical theory at a young age. He could also grow up with a greater understanding of the darker aspects of the wizarding world, like the prejudice against werewolves, which would make him more empathetic.
In the original Harry Potter story, Snape and Lily never had a baby. However, in fanfiction, authors can create alternate universes. They might rewrite the story so that Snape and Lily's relationship took a different turn. Maybe Snape was able to overcome his issues earlier and confess his true feelings to Lily before she got involved with James. This could potentially lead to a different timeline where they end up having a child together.
It could be due to a time - travel related plot. Perhaps Hermione goes back in time and through some unforeseen circumstances, her family line gets intertwined with Sirius' family, making her his sister in an alternate timeline. This could involve her interfering with past events that change family structures.