She could also change in how she approaches relationships. Before, as a boy, Sasuke was more reserved in his interactions with others, especially with Naruto. But as a girl, she might be more forward in expressing her feelings towards Naruto, whether it's friendship or something more. This could lead to some really interesting character development arcs and new plot directions in the fanfiction.
Perhaps the story could explore how the other characters react. The girls in the village might be more accepting of 'female Sasuke' and try to befriend her. The boys, on the other hand, might be a bit jealous of Naruto's close relationship with her. And this new form of Sasuke could also bring out new abilities or powers, or at least a different way of using her existing skills, which would make for some interesting battles and plot twists.
One possible plot could be that Sasuke uses some kind of rare jutsu accidentally while sparring with Naruto. This jutsu has the side effect of changing Naruto's gender. At first, Naruto is shocked and confused. But then, he (now she) starts to discover new aspects of the ninja world as a girl. For example, she might notice how differently she is treated by some of the male ninja. And Sasuke, feeling guilty, tries to find a way to reverse the effect while also protecting Naruto from any potential harm that could come from this new form.
Well, usually it starts with Naruto using some sort of jutsu or magic (in the fanfic world). Then Sasuke suddenly finds himself in a female body. At first, he might be really confused and angry. But as the story goes on, he starts to experience things differently as a girl. For example, he might notice how people treat him differently. Naruto might also start to see Sasuke in a new light, and there could be some really interesting character development and new relationships forming between them.
A common theme is identity crisis. Sasuke suddenly being a girl would make him/her question who they are now. Another theme could be acceptance, both from Sasuke herself and from the other characters. Also, there might be a theme of newfound friendship. As a girl, Sasuke might make new friends that he wouldn't have made before.
Naruto's personality might not change drastically at first. He would still be as determined and head - strong as before. However, as a girl, he might become more aware of how others perceive him. He could become more empathetic towards female characters in the ninja world, understanding their struggles better. Also, he might be a bit more cautious in some situations, especially when dealing with male characters who might act differently towards him now.
In addition to the obvious ones like Naruto and Sakura, other characters from Sasuke's clan might interact with him. For instance, if there are any remaining Uchiha members, they might have mixed reactions. Some could be shocked and try to figure out what happened, while others might be more accepting. Also, characters like Shikamaru, who is very observant, would surely notice the change in Sasuke and might have some unique interactions, perhaps trying to figure out how this change could affect their team dynamics or the overall situation in the village.
One possible scenario in this fanfiction could be that Naruto uses some sort of jutsu accidentally. Maybe he was trying out a new technique and it misfired, turning Kiba into a girl. In fanfiction, this could lead to a lot of humorous situations. For example, Kiba, now as a girl, might struggle with how to act or how to deal with the reactions of his friends like Shino and Akamaru. Also, Naruto would likely feel really guilty and try to find a way to reverse the transformation as soon as possible.
Well, perhaps a plotline could involve Sasuke turning into a girl and using this new form to his advantage in some undercover mission. He could infiltrate an enemy group more easily as a girl. Also, there could be a love triangle where some of the characters who previously saw Sasuke as a male now have different feelings towards him as a girl, which would create a lot of drama and conflict.
For Naruto, he might become more protective of Sasuke as a girl. Their friendship could take on a different dynamic, with Naruto being more chivalrous perhaps. Sakura might initially be jealous but then they could form a stronger bond as girls sharing common experiences. Kakashi would probably have to adjust his mentoring style to account for Sasuke's new situation.