Well, it could be that there was some long - lost adoption or a secret family tie that was covered up. Maybe Hermione was switched at birth and she actually has Malfoy blood in her veins. In the fanfiction, this discovery would likely cause a great deal of inner turmoil for Hermione as she has always been at odds with the Malfoys and their pure - blood supremacist views.
In some fanfictions, Hermione might find out she is a Malfoy due to a spell gone wrong. For example, a spell that was meant to reveal family lineages got mixed up and suddenly she has a connection to the Malfoy family in the magical world created by the fanfiction writer. It could also be a result of a hidden prophecy that links her to the Malfoys in an unexpected way.
One consequence could be that Hermione has to face the Malfoy family. They might try to bring her into their way of life, which she has always opposed. It would be a struggle for her to keep her own values intact while dealing with their pure - blood traditions.
She might struggle with her new identity at first. After all, she has always been seen as a Muggle - born. This new discovery could make her question her place in the wizarding world. She may start to explore her pureblood heritage, looking into her family's past and any special magical abilities or traditions that come with it.
She might start to search for her biological parents. This could lead her on an adventure full of mystery and self - discovery. She could use her intelligence and magical skills to track down any clues about her origins.
In this fanfiction, it could be that Hermione attends a wizarding symposium where the Zabini family is presenting some of their ancient magic. She is initially skeptical but as she listens to their presentation, she becomes intrigued by their knowledge and the way they approach magic. She starts to research more about them on her own, finding out about their famous ancestors and their influence in different areas of the wizarding world. As she delves deeper, she realizes she has a newfound respect and admiration for the Zabini family, thus becoming a fan.
It could also be a result of a magical bargain or curse gone wrong for the Malfoys. Suppose there was a powerful dark magic object in the manor that got out of control. Hermione, with her vast knowledge of magic, manages to contain it. In the process, she ends up being the rightful owner according to some ancient magic laws. This would make for an interesting plot twist in the fanfiction.
She could be shocked at first. Just imagine, she thought she knew her family all this time, and then bam, she's adopted. She might be angry too, especially if she feels she's been lied to. But also, she could be curious and eager to find out more about her real family.
Another way could be through a potion gone wrong. In the wizarding world, potions can have all sorts of strange effects. If Draco was trying to brew a potion for some other purpose, like trying to gain an advantage in a competition or something, and made a mistake in the ingredients or the brewing process, it could result in him being transformed into Hermione. This would force him to experience life from her perspective, which could be a huge character - development opportunity for him.
Discovering she's adopted in a fanfiction could change Hermione in many ways. Firstly, she may feel a sense of loss or confusion about her past. She has always been so confident in her knowledge and self, but this revelation could shake that. She might start to search for her real parents, which could lead her on all sorts of adventures. This could also cause some strain in her relationships with her adoptive parents if she feels they have kept this from her for too long.
Well, she might first be in shock. It could lead to a whole series of internal conflicts for Mal. She might question her identity and her place in the story world. Maybe she'll struggle with how to interact with Audrey from then on.
One great fanfiction with this theme is 'Hermione's Pureblood Revelation' on FanFiction.net. It delves into how Hermione discovers her pureblood heritage and how it changes her relationships at Hogwarts. She has to deal with the new - found knowledge and the expectations that come with being a pureblood in the wizarding world.