In such a fanfiction, one possibility is that Snape would initially struggle with his new role as an adoptive father. He has a complex personality, but over time he might start to show his protective side towards Harry and Hermione. He could teach them advanced magic, especially his own areas of expertise like Potions, in a more personalized way.
Dumbledore could play a significant supporting role in some versions. He might be guiding Hermione in her new role as Harry's guardian from the shadows. Neville Longbottom could also be a supporting character. He could be Harry's study partner when Hermione is busy, and they could exchange knowledge about different plants and potions. And of course, the Weasley family as a whole might be there to support them, with Molly Weasley perhaps cooking them delicious meals from time to time.
One possible plotline could be Hermione using her intelligence to create a stable and loving home environment for Harry. Maybe she helps him deal with his PTSD from his past traumas. Another could be them facing magical threats together as a family, with Hermione teaching Harry new spells and ways to protect himself.
At first, it would be really rocky. Harry has a history of distrusting Snape, and Hermione might be a bit cautious too. But as time passes, Snape's care for them in his own strict way would start to show. He'd probably be tough on them about their studies, but they'd see it's because he wants them to succeed.
I also recommend 'Adopted by Harry'. This fanfiction focuses on the impact of Hermione's new family situation on her Hogwarts life. It's quite heartwarming to see how Harry tries to give Hermione the family she never had and how she blossoms in this new environment.
One possibility is that Snape would be extremely strict with them at first. Given his past relationship with Harry especially, he might struggle to show affection openly. But over time, he could come to understand the trio better. Harry would likely be the most resistant to Snape's parenting at the start, but as Snape showed his genuine care, Harry might warm up. Hermione would probably be eager to learn from Snape, seeing his vast knowledge. Ron, on the other hand, might find Snape's gloomy demeanor a bit off - putting, but with Hermione and Harry's influence, he'd also adapt.
Well, it would change the story a great deal. Firstly, Harry would have a more stable home environment with Severus as his guardian. He wouldn't be so alone at the Dursleys'. Draco, on the other hand, might learn different values from Severus rather than just pure - blood supremacy from his family. And Hermione would have an adult figure in the wizarding world who truly understood her thirst for knowledge. The whole dynamic between the three of them would shift from rivalry to more of a sibling - like relationship under Severus' care.
Some people like it because it offers a different kind of family dynamic in the Harry Potter universe. It's a fresh take on the relationships between the characters.
A fanfiction titled 'Hermione's Refuge' has Remus adopting an abused Hermione. This story is unique as it not only focuses on Hermione's recovery but also on how Remus has to face the wizarding community's reactions. It shows that their relationship is not without challenges, but through it all, they support each other.
In such a fanfiction, Sirius might have to face various challenges while adopting Hermione. For example, there could be opposition from some parts of the wizarding community who might question his motives or his ability to take care of her. However, Sirius, with his strong will and love for Hermione, overcomes these obstacles. He might also help Hermione develop her magic skills further and give her the confidence she lacks due to the abuse she has endured.