A plot could be that Bella, as a vampire, has to pretend to be human around Alice's family. This would involve a lot of hiding her powers and dealing with the difficulties of being around humans all the time. Another idea is that Alice, as a human, discovers a way to make Bella more 'human - like' again, and they embark on a journey to find the ingredients or perform the rituals necessary.
One plot idea is that Alice, as a human, is being hunted by a group of vampires who want to use her as bait to get to Bella. Bella then has to use all her vampire skills to protect Alice and keep her alive. This could lead to some intense fight scenes and a deepening of their bond. Also, there could be a sub - plot where Alice starts to develop some sort of special ability because of her close proximity to Bella, which could change the course of the story.
One possible fanfiction could be about Bella adjusting to her new vampire life while Alice, as a human, has to deal with the knowledge of the supernatural world in a different way. Maybe Bella tries to protect Alice from other vampires who might see her as a target because of her connection to Bella.
A more character - centric plot could be about Rosalie and Bella finally coming to a true understanding and friendship. Alice could be the catalyst in this, arranging situations where they have to work together and learn about each other's pasts. This could include Rosalie sharing her human life story with Bella, and Bella sharing her fears and hopes for her new vampire life.
One plot idea could be a story where Bella, Rosalie, and Alice have to work together to solve a mystery in the vampire world. Maybe there's a new threat that only their combined skills can handle. Another could be a story focused on their friendship, like a road trip where they discover new things about each other and themselves. Or perhaps a story where they use their powers to help humans in a small town without revealing their true nature.
Well, a great plot might be that in a human - dominated world, Bella and Edward are trying to keep their true identities secret. But then, there's a series of mysterious disappearances in the town that they suspect are related to the supernatural. So they start to investigate together. Also, perhaps there's a prophecy in the supernatural world that involves a wolf - vampire - human bond, and they are unknowingly part of it. And this could lead to all sorts of adventures and challenges for them.
Well, one consequence could be that she has to distance herself from her human friends. Since she's now a vampire, she might be afraid of accidentally harming them. For example, her scent might be too alluring to them, and she could lose control. Also, her family relationships would change. Her father, for instance, would be left in the dark about her true nature, and she'd have to keep lying to him, which would create a strain on their relationship.
Maybe a plot where Jasper and Bella form an unexpected friendship that develops into a deeper bond. They could start by sharing their different experiences of being turned into vampires. Jasper could tell Bella about his past in the Confederate Army and how difficult it was for him to adapt to the vampire life initially. This could help Bella understand that she's not alone in her struggles. Then, as their friendship grows, they might face some challenges from the rest of the Cullen family who are a bit wary of their closeness.
One idea could be that Bella is a vampire from the start but has been in hiding. She could be on a mission to uncover a secret vampire society that has been causing trouble in the Twilight world. This would change her relationship with the Cullens as she'd be more of an equal, not a fragile human.
One plot idea could be that Jasper and Bella are high school students. Jasper is the new kid, and he and Bella slowly become friends and then fall in love. They face typical high school challenges like dealing with mean classmates and difficult exams together.
Maybe they both volunteer at a local community center. Through their work there, they discover they have a shared passion for helping the less fortunate. This common ground brings them closer together, and they have to navigate the challenges of their new - found relationship while also dealing with the opinions of their friends and family who don't understand their bond at first.
One idea could be a human detective falling in love with a vampire while investigating a series of strange murders in the city that are actually related to vampire politics. Another could be a human artist who meets a vampire at an old, spooky mansion and they bond over their shared love for art and beauty. A third idea is a human nurse who takes care of a wounded vampire and gradually falls in love as she discovers the vampire's kinder side.