Dumbledore may make an appearance in some fanfictions, even if it's just in flashbacks or as a guiding spirit for Harry and Hermione's family. His wisdom could be passed down through stories to their children. Also, characters like Hagrid might be involved, bringing his love for magical creatures into the family's life, maybe teaching the kids about how to care for them.
Hermione's family friends or neighbors in the muggle world can also be common characters. They can provide a contrast to the wizarding world she is part of. They might be curious about Hermione's newfound magical abilities or be involved in family gatherings where the two worlds collide. This creates an interesting dynamic and helps to explore different aspects of Hermione's family life.
Harry and Ron are very common. They are Hermione's closest friends, so they would be likely to be involved in helping her deal with the family curse.
Obviously, Harry and Hermione themselves are the central characters. Their spouses, if they have any in the fanfiction, would also be important. Their children would play a big role too, as they would be part of the new generation of the family. And of course, old friends like Ron, Ginny, and other Hogwarts alumni might make an appearance.
Neville could be a supporting character. He might be there to offer his unique perspective on things. Since he has his own growth arc in the original series, in the fanfiction, he could be a source of strength and advice for Harry and Hermione. Luna Lovegood is another possible supporting character. Her dreamy and wise nature could provide some interesting insights and help to Harry and Hermione as they navigate their new relationship and the challenges that come with it.
Another common character could be Hagrid. He was such an important part of Harry's life at Hogwarts and might continue to be in the fanfiction, perhaps coming over to the Potter family's house to show the kids some new magical creatures or give them some advice on their magical studies. There could also be characters from the Ministry of Magic, like some new Aurors who interact with the Potter family in different ways, either as friends or as those who are a bit suspicious of their activities.
Draco Malfoy is a very common character paired with Hermione. The contrast between their pure - blood and muggle - born backgrounds, along with their initial enmity, makes for a fascinating relationship to explore in fanfiction.
One common character paired with her could be Harry Potter. He might be working in Hermione's company, perhaps as her right - hand man in security or as an advisor on matters that involve the wizarding world's politics and power dynamics.
Harry and Ron are often still paired with her. Even if Hermione isn't human, they are her friends and they go through adventures together. Draco might also be paired with her in some stories. If Hermione is a non - human with special powers, Draco could be intrigued by her and they could develop an unlikely friendship or more. Snape could also be involved, maybe as a mentor figure to Hermione if she is a unique magical being.
There could also be new dark wizards or witches who envy the power and fame that Harry and Hermione have. They might see the child as a way to get to Harry and Hermione, or they might simply want to prove themselves by challenging the family. For example, a dark wizard who has developed a new and dangerous form of dark magic and wants to test it on the child.
Dobby is often a common character in such fanfictions. Since he was a well - known house - elf who managed to break free from his binds, he can be a source of inspiration or a mentor figure for other bound family elves in the stories.