Yes, there are. For example, in some fantasy novels, a magic spell might turn a male character into a girl. This often leads to a series of adventures as the character has to adapt to a new gender identity and the different social expectations that come with it.
Themes like identity crisis are quite common. The character suddenly becomes a girl and has to figure out where they fit in. Overcoming challenges related to the new gender is also a theme. For example, dealing with discrimination or different forms of treatment. And sometimes, there is a theme of finding love or friendship in the new form which shows how relationships can be different depending on gender.
In a magical forest, there lived a young adventurer named Jack. Jack came across a magical spring. Out of curiosity, he drank from it. Immediately, he started to transform into a girl. His clothes changed to fit his new form, and his voice became softer. Jack, now a girl, had to adapt to this new life. She started to make new friends among the forest creatures who accepted her regardless of her sudden change. This new life brought new challenges but also new joys as she discovered a whole new side of the forest that she hadn't noticed before as a boy.
The story of Marie Curie is a great one. She was the first woman to win a Nobel Prize and the only person to win it in two different scientific fields (physics and chemistry). Her discovery of radium was a huge breakthrough. This story can turn on a girl's interest in science as it shows that women can be at the forefront of scientific discovery.
One way to turn a character 'me' into a girl in a fanfiction could be through a magical transformation. For example, in a fantasy setting, the character might come across an ancient spell or a magical artifact that when activated, changes their gender. This could lead to all sorts of interesting plot developments, like having to adapt to a new social role as a girl in the story's world.
A story could be about a boy who stumbles upon a magic mirror. When he looks into it, it has the power to transform him into a girl. He finds himself with a new appearance, and he has to figure out how to handle things like going to school in his new form. He discovers that being a girl comes with its own set of rules and experiences that he never knew before.
There was a boy named Jack who made a wish to a fairy. The fairy, in a mischievous mood, granted his wish in a rather unexpected way. Jack woke up the next day as a girl. At first, he was shocked. But as time passed, he realized that he could see the world from a different perspective. He noticed how people treated girls differently, and he started to embrace his new identity, making new friends along the way.
One story could be about Malala Yousafzai. She defied the Taliban in Pakistan to fight for girls' education. Despite being shot, she continued her activism. Her story can turn on a girl's self - confidence as it shows that even in the face of extreme danger and opposition, a girl can stand up for what she believes in and make a huge impact on the world.
A really interesting 'turn into girl' story is one where a character in a video game gets cursed and turns into a girl. He has to complete quests and battles in this new form. It adds a whole new layer of challenge as he has to adapt to the different abilities and appearances that come with being a girl in the game world.