The boggart could be her fear of changing history too much. Since Hermione is so studious and respects the rules, she might be terrified of accidentally wiping out important events or people in the past during time travel.
One possibility is that the boggart represents her fear of getting stuck in a different time period. Imagine she travels back and something goes wrong with the return spell. The boggart could take on the form of a never - ending life in a time that's not her own, away from her friends and family. Also, it could be her fear of not being able to adapt to the different magical practices of another time. Hermione is used to Hogwarts' way of magic, but in a different era, magic could be very different. And this fear of being out of place in a time - travel situation could be what the boggart shows.
In time travel fanfiction, Hermione facing a boggart could be really interesting. Maybe the boggart takes the form of her failing in her time - travel - related tasks. For example, she might be afraid of causing a paradox that destroys the wizarding world she loves.
Perhaps the plot is centered around Hermione using time travel to save a loved one who was lost in a previous battle. She might have to navigate the complex rules of time travel, and along the way, discover secrets about the magic of time that no one knew before. This could lead to her having to make difficult choices between saving the past and protecting the present and future.
In some fanfictions, Hermione's Boggart of Ron failing at magic is a unique take. It shows her deep concern for him and how she secretly fears his lack of academic success in magic might lead to problems in their relationship. It's an interesting way to explore her character's insecurities.
In fanfiction, Severus Snape's boggart could be the lifeless body of Lily Potter. Since he loved her deeply and her death was a great tragedy for him. It would represent his ultimate fear of losing her all over again, even in the form of a boggart.
Well, through the boggart encounter, they might start with mutual dislike but as they see each other's fears, they could develop empathy. For example, if Hermione sees Draco's fear of his father, she might understand his tough family situation better. This new understanding could lead to a more civil relationship at first, like talking more in the hallways.
Hermione might be an ally to some of the Volturi members in the fanfiction. She could bring her knowledge and intelligence to help them in certain matters, like solving a mystery within their coven. For example, she could use her research skills to figure out the origin of a strange power that's affecting the Volturi. She could also be a mediator between the Volturi and other groups, using her diplomatic skills to ease tensions.
A possible plot is that the boggart takes the form of a combined fear for both of them. It could be a powerful dark wizard who has enslaved the wizarding world, and only Hermione and Draco, with their combined knowledge and skills, can defeat it. As they face this boggart, they learn to trust each other more than they ever thought possible.
One possible main antagonist could be a dark wizard from the past who senses Hermione's interference in the timeline and tries to stop her. This wizard might be afraid that Hermione's actions will change history in a way that will end his power or influence.
Well, perhaps the fanfiction explores how Draco has to face this unusual Boggart. He might initially be ashamed or try to hide it from others. But as the story progresses, through the help of his friends like Harry and Hermione (yes, an unlikely alliance in a fanfic), he starts to understand the root of his fear of Lucius and tries to change the family dynamic.
One significance is that it gives Hermione a unique ability. It sets her apart from other characters in the fanfiction world. She can use it to visit different eras and meet important figures from the past. This could lead to her learning new spells or magical theories that were lost over time.