One common theme is identity. Since she is Snape's daughter, she often struggles with defining herself apart from her father's complex legacy. Another theme is acceptance, both from the Hogwarts community and within her own family. For example, in many fanfics, she has to prove herself worthy to be in Slytherin like her father.
One great Severus Snape daughter fanfiction is 'The Snape Legacy'. In this story, his daughter has to navigate the complex world of Hogwarts while carrying the weight of her father's reputation. It shows her growth from a shy girl to a powerful witch, with interesting plot twists involving her relationships with other students and teachers.
There's also 'Shadows of the Past'. This one focuses more on the daughter's relationship with the other characters who knew her parents. She has to face the prejudices some have towards her because of her father, while also trying to uphold the good name of her mother. The plot is full of twists and turns that keep you hooked from start to finish.
In some fanfictions, her plot could revolve around time - travel. She might accidentally travel back in time and meet her father when he was a student. This would give her a chance to see a different side of him and understand his choices better. She could also try to change some events in the past to make a better future. However, this would bring a lot of consequences and she would have to deal with the butterfly effect in the wizarding world.
One common theme is identity. Since she is the daughter of two such important and complex figures, she often struggles to figure out who she is. Another theme is legacy. She has to deal with the legacies of both Snape and Lily, which can be both a burden and a source of strength.
Yes, in some fanfiction, Severus Snape is depicted as a vampire. Fanfiction allows for creative interpretations of existing characters, and making Snape a vampire can add an interesting and often dark twist to his character.
For writing her character, you need to think about her place in the wizarding world. She's the daughter of a controversial figure. So, she might be constantly in the spotlight. This could make her either shy away from attention or use it to her advantage. Her magical abilities should also be developed in a way that makes sense. Maybe she has a natural aptitude for some spells that Snape was also good at, but she struggles with others. Her relationship with her peers is crucial too. She could be a bit of an outcast at first, but as the story progresses, she forms deep bonds. You can also explore her emotions towards her father's death and how it affects her growth as a witch.
One possible plotline could be the daughter's struggle with her father's complex reputation at Hogwarts. She might face prejudice from students who remember Snape's dark past. Another could be her discovery of her father's true love for her mother, which was hidden for so long. And she could also have a special talent in potions, just like her father, and use it to outshine others in her classes.
In some fanfictions, Snape has badass moments when he outsmarts Voldemort. For example, he manages to mislead Voldemort about the location of a crucial magical artifact. He uses his Occlumency skills to his advantage, hiding his true thoughts and intentions while presenting false information in a very clever way. This not only shows his intelligence but also his courage as he risks his life to deceive the Dark Lord.
Well, Harry Potter would likely still be a main character. His relationship with Snape could be even more complex in this fanfiction. Since Snape is a demigod, Harry might be both in awe and a bit scared of him at times.