In a fanfiction, Ginny could be out to get Hermione because of a prophecy or some sort of ancient magic that pits them against each other. Maybe there's a hidden aspect of their characters' destinies that was never revealed in the original series. For example, a prophecy that only one of them can fulfill a great task at Hogwarts, and Ginny, believing it should be her, decides to undermine Hermione.
I'm not sure specifically if there is a fanfiction with exactly that premise. But given the vast world of fanfiction, it's very possible. It could be an interesting take on the characters, but also a rather strange one considering Ginny and Hermione are friends in the original story. Maybe in this fanfiction, the author has a unique backstory or reason for Ginny to be 'out to get' Hermione, like a misunderstanding or some new plot device.
In a fanfiction, it could be that Ginny is being too reckless. Hermione, being the more cautious one, is always worried about getting into trouble. If Ginny is constantly sneaking out or getting involved in dangerous adventures, Hermione might yell at her to stop putting herself and others at risk.
A simple outcome could be that they have a heated argument and then make up quickly. They realize they both care about the same things in different ways. For example, they both care about their friends' well - being but just have different approaches.
In this fanfiction, it could be that Ginny is involved in some sort of gossip or spreading rumors. Hermione, who values truth and integrity, confronts Ginny about it. She might scold Ginny for being irresponsible with her words and how it can harm others' reputations at Hogwarts.
One possible reason could be jealousy. Maybe Ginny is jealous of Hermione's close friendship with Harry or her academic achievements. In the wizarding world, relationships can be complex, and Ginny might feel overshadowed by Hermione at times.
It could also be related to a boy. If both Ginny and Hermione are interested in the same guy, say Harry Potter, Hermione might stand up to Ginny to assert her own feelings or to clarify some misunderstandings that Ginny has about her relationship with the boy. This can create a tense situation between them in the fanfiction.
In many fanfictions where Hermione confronts Ginny Weasley, it often stems from a conflict over a boy, like Harry. Hermione might feel that Ginny is being too forward or not taking Harry's feelings into account. For example, if Ginny is making big moves on Harry without considering how it affects his studies or his mental state, Hermione, being the practical and studious one, could confront her. It could also be about their different personalities clashing in the context of the wizarding world's social dynamics.
Well, Hermione has a unique charm. In fanfiction, Bill could be attracted to her because of her strong sense of justice. She is always fighting for what's right, and Bill, who has seen a lot in the wizarding world, might admire that. Also, her loyalty to her friends is something that could draw Bill to her. He might see in her a kindred spirit in terms of being there for those he cares about.
It could be due to jealousy. Perhaps Ginny has been spending a lot of time with another character, and Harry misinterprets their relationship, leading to his anger. In fanfiction, the writers often play with such emotions to create drama.
In some fanfictions, Ginny might be written to betray Harry because of a prophecy. The prophecy could mislead her into thinking that Harry was going to bring doom, and so she decides to act against him to prevent that. It's a different way of looking at their relationship compared to the original story, where their bond was based on love and trust.