Some fanfics have the plot where the OC aunt is an outcast from the wizarding community for some reason. But she overcomes this when she starts to help Harry. She might have been wrongly accused of a crime in the past. As she helps Harry, she also clears her own name. This makes for a very engaging story as there are two parallel storylines of her redemption and Harry's growth. In addition, there are often sub - plotlines about her making new friends and allies in the wizarding world who initially were skeptical of her.
In the plot, she could be a link to a part of the wizarding world that Harry has not yet explored. Say she is part of a secret society of witches and wizards. By introducing Harry to this group, it could open up new storylines such as learning new types of magic, getting involved in political intrigue within the wizarding world, or even finding new allies in his battle against Voldemort.
Maybe the aunt is a half - blood who has a foot in both the Muggle and wizarding worlds. She could be an artist who uses magic in her art, creating paintings that come to life. In fanfiction, she could help Harry see that there are different ways to use magic beyond just spells for combat or everyday tasks, and she could also be a source of comfort during his tough times at Hogwarts.
One great 'Harry Potter OC Aunt' fanfiction is 'The Aunt from Afar'. It tells the story of an OC aunt who has magical powers and has been in hiding but resurfaces to protect Harry. She has her own unique backstory and her relationship with Harry is really heart - warming.
In the fanfiction, they could be forced to work together on a project related to lemons. Maybe there's a local fair that requires everyone to contribute something lemon - themed. Through this shared task, they begin to understand each other better. Harry realizes that Aunt Marge has her own insecurities and Aunt Marge sees that Harry is not the troublemaker she thought he was. For instance, Harry could show his creativity and intelligence during the project, impressing Aunt Marge.
One possible fanfiction could be about Aunt Petunia having a strange encounter with a lemon - themed magical object. Maybe she accidentally uses it in a spell (in a non - canon, fan - created way) that makes her see a different side of the wizarding world she has always despised. This could lead to her having a change of heart about Harry Potter and his world.
Aunt Lemon might also impact Harry's life by introducing him to a different side of the Muggle world. Maybe she has a love for art or music, and through her, Harry discovers these aspects of Muggle culture that he otherwise would have been deprived of. This newfound interest could help him better understand the differences between Muggles and wizards and appreciate both worlds.
One possible fanfiction could be about Aunt Petunia discovering her latent witch powers late in life. Maybe she starts having strange dreams that lead her to an old family heirloom that unlocks her magical abilities. She then has to deal with the shock of it all while also trying to keep it a secret from the Muggle world around her.
Well, it could be quite strange. Maybe she's secretly a bit more interested in the wizarding world than she lets on. It might be a way for her to explore the stories from a different perspective, one that's not as judgmental as her usual self towards magic.
There could be a fanfiction where Aunt Marge discovers she has some magical ability herself. This would completely change her view of the wizarding world and her relationship with Harry. She might end up joining Harry on some of his adventures, much to everyone's surprise.