If Hermione was Harry's sister, it would add a new layer of complexity to the story. Maybe they'd have more inside jokes and a unique way of communicating. Plus, it could affect how they handle conflicts within the wizarding world, standing even more united.
Well, if Hermione was Harry's sister, it would likely impact the way they approach challenges and adventures. They might have more shared family concerns and a deeper sense of loyalty. Also, their interactions with other characters could be different as their family status has changed.