Well, it could be a story about family secrets. Maybe Bella has just discovered that Billy is her father and she has to deal with the shock of this new information while also getting to know Billy and his side of the family.
Perhaps the fanfiction could center around a magical or supernatural element. For example, if they live in a world with special powers, Bella's discovery of being Billy's daughter could unlock some hidden powers within her. Or it could be that Billy has some sort of special mission that he now realizes Bella is a part of because of their relation, and they have to embark on an adventure together to fulfill that mission, all while developing their father - daughter bond.
If it's set in a school or work environment, Bella's friends or colleagues could be main characters. They might notice the changes in Bella as she discovers this new family connection. Also, if there are antagonists in the story, it could be someone who doesn't want Bella and Billy to form a relationship. This could be someone who has a grudge against Billy and sees Bella as a way to get to him, or it could be someone who is jealous of Bella getting a new family.
In a 'bella is thor's daughter fanfiction', the plot could involve Bella being whisked away to Asgard. There, she has to learn about her father Thor and the ways of the Asgardians. She might get into trouble with the other Asgardians who are skeptical of her because she's from a different place. But as she proves herself, she could form alliances and help Thor in some great battle or quest, all while coming to terms with her new identity.
One possible plot could be Bella growing up not knowing who her father is. Then, as she discovers her true identity, she has to decide whether to follow in Voldemort's dark footsteps or rebel against him. She might face a lot of internal conflict as she tries to balance her own values with the legacy of her father.
Well, it could be about Damon having to protect Bella from the various threats in their supernatural world. Maybe she has some unique powers that draw unwanted attention.
One possible plot could be Bella growing up in a world filled with the supernatural elements that Rebekah is a part of. Maybe she discovers her powers early on and has to learn to control them while also dealing with the complex family dynamics of being Rebekah's daughter. For example, she might face the expectations of the vampire community that Rebekah is associated with.
Well, it could be about Bella trying to break free from her father's, the Joker's, evil influence. Maybe she has a good heart in contrast to him and wants to use her skills for good, like helping Gotham in a more positive way.
Well, it could involve Bella discovering her true heritage as Elijah's daughter. Maybe there are conflicts with other characters who have different intentions regarding her. For example, some might want to use her for power, while she just wants a normal life.
Well, it could be about Bella having some sort of special relationship with a tiger. Maybe she has the ability to communicate with it on a deeper level, like they share a telepathic bond. And she might go on adventures with the tiger, protecting the forest or something.
One possible plot could be Bella's journey to discover more about her father Joshua. Maybe she stumbles upon some of his old secrets or talents that she never knew about. This could lead to a series of adventures as she tries to understand who he really was in his youth and how it has influenced her life.
Well, one possibility could be that Bella Swan has to deal with the chaos that comes with being the Joker's daughter. Maybe she struggles to balance her normal life, like in Forks, with the dark and unpredictable world of her father. She might have some of the Joker's traits, like a wild sense of humor but also a bit of madness that she has to control.