In such fanfiction, it could add a new dynamic to the story. Maybe she inherits some of Sirius' traits and faces her own adventures in the wizarding world.
There probably is. The Harry Potter fandom is huge and full of diverse ideas. Writers might explore this idea to add new twists to the story, like how Harry's relationship with Sirius would be re - imagined if he were his daughter, and how it would change the overall plot dynamics.
In fanfiction, such a plot might seem very out of character for Sirius Black. In the original series, Sirius is a loving and loyal character. This could be a very dark and angsty take in the fanfic. Maybe the writer wants to explore complex family dynamics or some kind of tragic backstory that led to this situation. However, it goes against the general perception of Sirius as a heroic and loving figure.
One idea could be that Sirius Black's daughter, who has been hidden away all this time, discovers her true identity while trying to break into Azkaban to clear her father's name. She could have some unique magical abilities that help her in this dangerous quest.
One interesting fanfiction could be about Sirius Black's daughter joining Harry Potter and his friends on their adventures at Hogwarts. She might inherit her father's brave and rebellious spirit, causing some interesting twists in the story.
In some fanfictions, the mother could be a character that was only briefly mentioned in the original series. For example, it could be a witch he knew from his school days at Hogwarts. They reconnected later in life and had a daughter. Or, it could be a new character who has a special connection to the Black family, perhaps a distant relative who got closer to Sirius and they had a child together.
Well, in the fanfiction world, 'Sirius Black's Daughter: A New Hope' is quite interesting. It shows how the daughter, with her unique abilities, tries to make a name for herself in a post - Voldemort era. It has a great plot that weaves in elements of mystery and adventure. There is also 'Daughter of the Marauder' which is known for its detailed character development of Sirius Black's daughter.
Obviously, the daughter of Sirius Black is the main character. She is often depicted as having some of her father's rebellious spirit. Her friends at Hogwarts also play important roles, like her best friend who might be from a different house, adding an element of inter - house friendship.
She could be seeking revenge against those who wronged her father. So she goes to Azkaban, using her father's old contacts and knowledge, to find the real culprits. She might be a powerful witch, with skills in Occlumency to protect her mind from the dark influences in Azkaban.
I've read a fanfic called 'Time - Twisted Daughter'. In this story, the daughter's time travel is an accident. She ends up in the past and has to figure out how to get back while also dealing with the chaos of being in a time where her father is still a student at Hogwarts. It's full of mystery and adventure.