Hermione could become more attuned to the darker aspects of magic. With Remus being a werewolf and Sirius having his own dark family history, she might explore the gray areas of magic more. For example, she could study more about the dark arts not to practice them, but to understand how to better defend against them. This would be a significant shift from her canon character who mostly stuck to the 'light' side of magic study.
Hermione could develop a more complex personality. On one hand, she has her intelligent and studious self from growing up in the wizarding world as we know it. But on the other hand, she may have a new, darker side emerging due to her connection to Bella and Rodolphus. This could lead to her being more of an outcast among her friends, and she would have to work hard to prove that she is not like her Death Eater parents.
There are some really interesting fanfictions on this concept. One I remember had Hermione growing up with a unique blend of Remus' calm wisdom and Sirius' rebellious spirit. It was fascinating to see how she navigated Hogwarts with that background.
A new storyline might involve Hermione exploring the secrets of her fathers. She could learn about Sirius' family secrets and Remus' experiences as a werewolf in a more personal way. This could lead to her finding new ways to fight against dark magic, as she combines the Gryffindor courage from Sirius and the Ravenclaw wisdom from Remus. It could also create a lot of drama as she tries to balance her old life with this new revelation of her parentage.
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.
They might be interested in adventure - themed fanfictions where Hermione goes on some exciting quests. For example, she could be exploring ancient magical ruins or trying to solve a mystery that even Dumbledore couldn't figure out.
She could develop a more guarded personality. In Slytherin, she'd learn to protect her thoughts and feelings more, as the house has a reputation for being shrewd. Her confidence might also take on a different edge, becoming more self - assured in a slytherin - like way. For example, she'd be more likely to speak up when it benefits her and the house directly.
She becomes more confident. With Sirius' boldness and Remus' intelligence guiding her, she's more willing to take risks. For example, in some fanfictions, she might be more likely to stand up to bullies at Hogwarts.
She could have a very different relationship with Harry. Instead of being just friends, she might be more like an older sister figure, using her family knowledge to guide him. With Ron, their relationship could be more complex. Maybe there would be some jealousy from Ron as Hermione would have a more prestigious family background. And with the other members of the Black family, she would have a family bond. Some of the Black family members who were against Voldemort could be her allies in a more personal way.
Typically, in such fanfiction, there would be a complex relationship dynamic. Sirius and Remus, who are from an older generation in the Harry Potter world, would have an interesting connection with Hermione. There might be elements of mentorship mixed with unexpected emotional bonds.