Typically, it might start with the discovery of their relationship. Maybe Hermione shows some unexpected abilities that link her to Natasha. Then, they could go on adventures together, with Hermione's magic and Natasha's fighting skills complementing each other.
Natasha would likely become more maternal. She'd start to show a softer side that she usually hides. For example, she might be more patient with Peter when he makes mistakes during training, which is different from her normal no - nonsense attitude.
Typically, in these fanfictions, Hermione's identity as Voldemort's daughter shakes up the whole wizarding world. It usually starts with her being the only one aware of this fact. As she tries to come to terms with it, she may start to have strange dreams or visions related to Voldemort's past. These could provide her with clues about his motives and the secrets of his dark magic. Her relationship with other characters changes drastically. Her friends might be initially distrustful, but as the story progresses, they come to see that Hermione is still the same person they knew. Meanwhile, Hermione might be on a quest to find out if there are any other family members she has on her father's side, which could lead to more adventures and revelations.
One way the storyline could develop is that Hermione would struggle with her identity. She might initially be in denial about her father's Death Eater past. For example, she could discover it accidentally and then have to face the prejudice from her friends at Hogwarts. This would create a lot of internal conflict for her as she has always been a defender of justice and against the Dark Arts.
Yes, there are some interesting ones. You can try searching on fanfiction websites like Archive of Our Own. Some stories might focus on how Hermione's magic and Natasha's combat skills combine in unique ways within the story's universe.
At first, their relationship might be a bit rocky. Peter is a young, energetic kid and Natasha is used to a more serious, stealthy lifestyle. But as time goes on, Peter's innocence and eagerness to learn could start to win Natasha over. She might start to see him as a little brother or someone she needs to protect.
In some Infinity War fanfictions, Natasha might develop by becoming more of a strategic leader. As the situation gets more dire with Thanos approaching, she could step up and start making tough decisions that show her growth in leadership skills.
Typically, it starts with the revelation of the unexpected relationship. Then, Hermione often has to deal with the stigma of being related to a Death Eater. She might struggle with her own identity, wondering if she has any of Rodolphus' traits. Some storylines have her trying to redeem the family name or break away from the dark past associated with it.
At first, they might be a bit awkward around each other as they get to know each other. But over time, they could start to bond over shared interests. For example, if Rossi is into detective work, Hermione's sharp mind from her years at Hogwarts could help her assist him in solving cases.
He'd be more cautious. Natasha is a spy, always aware of her surroundings. Harry would learn to be like that. He'd be less likely to rush into things without thinking.
It would have a huge impact on the Avengers. Firstly, they would be more protective of her. Her pregnancy would make her a more precious asset to the team, not just as a fighter but as someone carrying new life. So, they might assign more bodyguards to her or keep her out of the most dangerous situations.