One idea could be that Harry's little sister has a unique magical ability that no one else in the family has. For example, she might be able to communicate with magical creatures in a way that even Hagrid is impressed by. This could lead to all sorts of adventures where she helps solve problems in the wizarding world using this special skill.
Yes, there are quite a few. Some explore how a sister would change the dynamic of Harry's family and his adventures at Hogwarts. For example, she might be an additional source of support for Harry or have her own unique magical abilities that come into play during the fight against Voldemort.
One common theme is family. Since it's about Harry having a little sister, it often explores the family dynamic. How they support each other, protect one another, and sometimes even have sibling rivalries. Another theme is identity. The little sister has to figure out who she is in the shadow of her famous brother.
The Weasley family would probably play a role too. Ginny could be a role model for the little sister, especially in terms of being a strong female witch. Fred and George might teach her some of their pranks or tricks. And Mrs. Weasley could be like a second mother to her, showing her the warmth of a family. The Malfoys could also be in the story, perhaps as antagonists, creating conflict for the little sister and Harry.
Well, often the sister is used to explore family relationships more deeply. Maybe she has memories of their parents that Harry doesn't, which helps him understand his family history better. Also, a lot of these fanfictions have the sister being sorted into Gryffindor like Harry, and they become a duo that everyone at Hogwarts looks up to. They face challenges together, like dealing with bullies or difficult professors, and their bond grows stronger through these experiences.
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.
In a 'Harry Potter and His Little Sister' fanfiction, the sister could be a new student at Hogwarts when Harry is in his later years. She struggles to fit in because of being Harry Potter's sister. Harry has to help her deal with the pressure, make friends, and also face the threat of a new dark wizard who has a vendetta against the Potter family.
One interesting plotline could be the little sister discovering she has her own unique magical abilities that are different from Harry's. For example, she might be able to communicate with magical creatures in a way no one else can.
One great Harry Potter little sister fanfiction is 'The Potter Siblings' on FanFiction.net. It delves into the relationship between Harry and his fictional little sister in a really heartwarming way. The story shows how she grows up in the shadow of her famous brother yet manages to carve out her own identity within the wizarding world.
Well, obviously the little sister herself is a very important character. Depending on how she's written, she could be really kind - like a Hufflepuff at heart - or really brave and adventurous like a Gryffindor. Then there are the classic characters from the original series that often play a big role. Hermione would likely be there to offer her wisdom and help the little sister with her studies. Ron would be the comical friend, always getting into some sort of trouble but also being very loyal.