Who could be the main characters in a 'Harry Potter raised by his older sister' fanfiction besides Harry and his sister?

The sister might have her own group of friends in the wizarding world. When she takes in Harry, she brings him into this circle. They all contribute to his upbringing. For example, one friend could be a potions expert and teach Harry about potions in a fun way. Another could be a great dueler and train Harry in combat magic. His sister coordinates all this, ensuring Harry gets a well - rounded magical education and a loving family environment.

Ron could also play an important role. He could be a bit jealous at first of the close bond between Harry and his sister, but then they become friends. Ron's sense of humor and loyalty would make him a fun addition. He could be involved in their adventures, like when they go looking for Horcruxes, and provide some comical relief during tense times.

Ron and Hermione are likely to interact with them. Ron might be a bit more protective of the sister, while Hermione would probably study and share knowledge with her. They could all be in the Gryffindor common room, discussing spells and strategies.

It could be a dark wizard who is jealous of the Potter family's fame and power. He sees Lemon as an easy target to get to Harry and plans to use her to lure Harry into a trap.

She could be a half - blood like Harry. Maybe her mother was a muggle - born witch and her father was a pure - blood wizard. This mixed heritage could give her a unique perspective on the wizarding world's issues regarding blood purity.

Harry and Lemon are the stars of this fanfiction. Harry could be a character with a lot of hidden potential that he discovers throughout the story with the help of his sister. Lemon, on the other hand, may have a special gift like being able to communicate with animals. Their different personalities and abilities are what drive the story forward as they face various challenges together.

There could be the Guardians. They might play a role in the story. For instance, they could be initially hesitant about Jack Frost's sister being around, fearing she might disrupt the balance. But as they get to know her, they become friends. North could be there, with his jolly self, giving the sister a little magical gift.

Voldemort's remaining followers could be antagonists. They might target Harry's little sister thinking they can use her to get to Harry. They could try to kidnap her or use dark magic on her.

Hermione could be there. She would be really helpful in planning and organizing the island. For example, she might set up a system for categorizing all the magical knowledge and resources on the island.

One possible reason could be jealousy. Maybe the sister is getting more attention from their parents or at Hogwarts. For example, if she is a star student and Harry feels overshadowed.