Well, it could be a story full of challenges. Hermione, being a clever and kind - hearted witch, would face a lot of prejudice. People might be scared of the child because of its relation to Fenrir. But Hermione would use her intelligence to educate the child, showing that one's origin doesn't define who they can become. She'd probably introduce the child to the wizarding world in a positive way, despite all the difficulties.
Harry would probably be very supportive. He knows what it's like to grow up without parents, and he would see Hermione's decision as a very kind and noble one. He might offer to help in any way he can, like teaching the child some of his own skills in magic or defense against the dark arts.
One possible storyline could be that Hermione, having witnessed the hardships of war and the many orphaned children, decides to adopt a child. She might choose a child who shows magical potential but has been overlooked in the post - war chaos. The story could then focus on her struggles and joys of raising the child while also dealing with her own career and the expectations of the wizarding world.
She would probably surround the child with a network of trustworthy friends. Harry and Ron could be part of that. Their combined influence and power in the wizarding world could act as a deterrent to those who might want to harm the child. Hermione would also use her own reputation as a brilliant witch to vouch for the child's good nature.
One common theme is the idea of redemption. Fenrir is often seen as a villain, and through his adoption of Harry, he may find a path to redemption. For example, in some stories, he starts to care for Harry and in the process, he changes his ways.
At the start, Hermione would be appalled by Fenrir's cruelty. She would be enraged that he has caused so much harm to innocent people. But as she delves deeper into getting to know him, she would start to see the complex web of factors that contributed to his behavior. She might see the neglect and discrimination he faced as a werewolf, which could make her feel a bit of pity. However, she would still firmly oppose his cruel actions and try to find a way to either contain or reform him, all while being acutely aware of the danger he poses.
It could be an orphaned wizard child from a family that was killed by Death Eaters. This would give Snape an added sense of responsibility as he might feel guilty for being associated with the Death Eaters in the past.
I'm not sure if there is such a specific fanfiction. It seems like a rather dark and unusual pairing considering Fenrir Greyback is a werewolf known for his brutality. However, the world of fanfiction is vast, and there might be some out there that explore this concept, but it's not a common or mainstream idea in the Harry Potter fanfiction community.
There's also 'Hermione and Fenrir: A Different Kind of Magic'. This story focuses on the cultural and magical differences they have to overcome as they form their bond. It shows how Hermione's intelligence and Fenrir's wild nature interact in a unique way. The author does a great job of creating a believable relationship between the two characters within the wizarding world's context.
Well, one possibility is that Harry realizes Fenrir's tragic backstory and decides to help him change. Maybe he uses magic to suppress Fenrir's werewolf side and tries to integrate him into the wizarding society. Harry could teach Fenrir about friendship and loyalty, and together they fight against the dark forces that once exploited Fenrir.