He could have different interactions with the Hogwarts teachers. Teachers like Professor Snape might treat him (as Hermione) with a bit more respect due to Hermione's academic achievements. Harry could also use this opportunity to learn more about the inner workings of Hogwarts from the perspective of a different student. He might discover new secrets in the library or during private study sessions with professors that he wouldn't have as Harry.
One possibility is that they become involved in the fight against dark magic in America. Since they have experience from their time in Britain, they could offer their skills and knowledge. They may also explore the different magical cultures within America, from the Native American magic to the magic practiced in big cities like New York. Their move could be a chance for them to expand their understanding of the magical world on a global scale.
It could reveal new adventures in the Forbidden Forest. Hermione might take the lead in exploring the forest, using her knowledge to navigate the dangerous areas. She could encounter new magical creatures and try to study them while also ensuring her and her friends' safety.
One new adventure could be that they discover a family heirloom together. Since they are siblings, they might start looking into their family history more deeply. Maybe there's a hidden magical object that only their family line can access, and they go on a quest to find it.
A new adventure could be related to a family - owned magical property. It could be a house or a piece of land that has been enchanted and is now in danger. Harry and Hermione, as siblings, would feel responsible for protecting it. They would need to figure out the source of the danger, whether it's a dark magic curse or a group of greedy wizards trying to take it over. This would lead to a series of exciting events as they use their combined wits and magic to save their family's property.
One reason could be Hermione's excessive worrying. She often frets over small details and Harry might get tired of it and tell her off. For example, if she keeps nagging about the proper way to perform a spell when they are in a hurry during a dangerous situation.
Maybe she's yelling at Ron. Their relationship in fanfictions can be quite complex. If Ron says something insensitive or does something stupid, like forgetting an important task that could put their mission in jeopardy, Hermione would surely yell at him.
The child could go on an adventure to discover a long - lost magical artifact that has been hidden for centuries. It might be something that was once in the possession of one of the founders of Hogwarts.
Well, first of all, Harry and Ron would be extremely confused and worried. They would probably try to hide her from the other students and teachers at first. If she was found out, it could cause a big panic in Hogwarts. Some students might be scared and run away, while others might be curious. And Hermione, as a troll, would have to deal with her new form. She might find it difficult to move around in the castle, as trolls are much bigger and less agile than humans in the narrow corridors.
Another motive might be related to a dark object influencing her. If Hermione came across a cursed object, like a dark locket that amplified negative emotions such as envy or fear, it could drive her to kill Harry. Maybe she started to envy Harry's fame and the special attention he always got, and the locket pushed her over the edge.
Yes, there are quite a few fanfictions out there that depict Hermione and Harry kissing. Fanfiction allows for different interpretations of the characters' relationships. Some writers might explore a romantic connection between them that wasn't fully developed in the original series.