Perhaps the plot could involve Petunia having some sort of magical awakening or discovery that leads her to perform this transformation on Harry. In this fanfiction, Harry might then use her new female identity to infiltrate parts of the wizarding world that are more difficult for a male to access, like certain all - female magical groups. And this could lead to all sorts of adventures and revelations about the wizarding world's gender dynamics.
In the 'Petunia Turns Harry into a Girl' fanfiction, the plot could center around the chaos that ensues in the Dursley household. Petunia might have done it out of spite or some strange magical experiment. As a girl, Harry could face different challenges at Hogwarts too. Teachers might treat her differently, and she might have to deal with new forms of bullying or admiration. There could also be a sub - plot about Harry trying to find a way to reverse the transformation while still making the most of her new situation.
Petunia's character could also develop in this fanfiction. If she turns Harry into a girl, she might start to feel guilty or responsible. This could lead to a change in her relationship with Harry. Maybe she would start to see Harry as more of a person rather than just a burden. And she could also develop some magical abilities further as she has now performed such a complex spell on Harry.
I'm not entirely sure as 'lemon' often implies adult content in fanfiction, but if we assume it's a non - adult take, perhaps Harry could dominate Petunia in terms of magical knowledge. Maybe he shows her the true power of magic and she has to accept his superiority in that regard.
They can make the plot more complex. If Petunia is suddenly nicer to Harry, it changes the dynamic at the Dursleys' house. Harry might not be as eager to leave for Hogwarts, or he could have a different attitude towards Muggles in general. For example, if Petunia helps him with his magic studies secretly, he could be more advanced when he gets to Hogwarts, which would change his interactions with classmates and teachers.
One possible plot could be that Harry shows a special talent early on that Vernon and Petunia recognize as something extraordinary. This makes them see Harry not as a burden but as a valuable part of the family. They then start to love and protect him, and this changes Harry's life completely. He no longer has to endure the abuse and neglect he faced in the original story.
One great Petunia fanfiction could be one where she has a moment of self - realization. Maybe she discovers some of Lily's old magic things and starts to understand the wizarding world better. It could show her in a more sympathetic light, perhaps she even tries to protect Harry in her own way.
Well, it depends on the specific fanfiction. Some fanfic authors like to play around with the relationships and concepts in the Harry Potter universe. So it's possible that in certain fanfictions, Petunia is Harry's pet. However, in the canon story, Petunia has a very different role as Harry's rather unfriendly aunt who begrudgingly takes him in. But fanfiction allows for all kinds of creative interpretations.
One possible plot could be that Petunia is somehow magically enslaved by a dark wizard. Harry, upon finding out, feels a sense of obligation to save her. He might have to use his knowledge of magic and his connections at Hogwarts to figure out a way to break the spell. Along the way, he could discover some secrets about Petunia's past that were related to the wizarding world.
Maybe there's a fanfiction where the lemon is a key ingredient in a potion. Lily was working on this potion before she died, and Petunia knew about it but never told Harry. Harry discovers this secret and starts to research the lemon - based potion. As he delves deeper, he uncovers more about his mother's intentions and the relationship between Lily and Petunia. It could be a story full of mystery and self - discovery.
The plot could start with Petunia having a strange encounter with an angel. The angel seems to know things about her past and her relationship with Lily. At the same time, an elf, which has been observing Petunia for some reason, decides to approach her. The angel wants to help Petunia understand the importance of magic and her family's place in it. The elf provides some practical help, like getting access to some magical items. As the story progresses, Petunia changes her view of the wizarding world, and together with the angel and the elf, they might even influence some of the events in the wizarding world, like helping to protect Hogwarts or something similar.
If Petunia was a witch, it would completely change Harry's upbringing. He might have learned magic from her instead of being in the dark until he received his Hogwarts letter. This would make him more confident and perhaps less of an outcast in the Muggle world.