Another plot could be that Bella develops a possessive streak towards Rosalie's beauty and grace as a vampire. Bella, feeling insecure about her own new vampire self, tries to keep Rosalie close to learn from her. This possessiveness could lead to an interesting dynamic where Rosalie is both flattered and annoyed at the same time.
One idea could be that Bella discovers Rosalie's possessive nature towards her new vampire life. Rosalie might try to control Bella's actions to prevent her from making what she sees as mistakes. For example, Rosalie could be possessive over the 'right' way to be a vampire and try to keep Bella from straying from it.
Perhaps in the fanfiction, Rosalie becomes possessive of Bella's relationship with Edward. She might see Bella as someone who has an easy love with Edward while she had a difficult past. So, she tries to interfere in their relationship, creating a lot of drama and tension between the three of them.
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 idea could be that Bella and Rosalie have to team up to protect the Cullen family from a new vampire threat. They start off disliking each other but as they face challenges together, they develop a mutual respect.
One plot idea could be that Rosalie and Bella discover a hidden power within their futa forms that is connected to the supernatural world around them. They then have to navigate how to use this power while also dealing with the reactions of their friends and family in the Twilight universe.
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.
A third plot might involve a mystery in the modeling world. Bella, Alice and Rosalie are models, and suddenly, there are strange disappearances of models from their agency. They decide to investigate. As they dig deeper, they find that there is a jealous rival trying to sabotage their agency. They use their different skills - Bella's tenacity, Alice's intuition and Rosalie's beauty and charm - to expose the culprit and save their agency.
The possessiveness of Bella and Rosalie can cause a great deal of unrest within the Cullen family. For instance, if Rosalie is possessive of her vampire 'ideals' and Bella starts to oppose them, it can create a divide. The family might have to take sides, which could lead to internal conflicts.
One plot idea could be that Bella and Rosalie have to team up to protect the Cullen family from a new threat in Forks. Along the way, they start to realize their feelings for each other are deeper than just friendship. Another could be a story where they go on a road trip together to find a rare vampire artifact and during that journey, their relationship blossoms. Maybe they start off as rivals within the Cullen family but then find common ground and fall in love.
One idea could be that they meet in an unexpected place like a small, out - of - the - way coffee shop. Rosalie is there reading a book and Emmett accidentally bumps into her table. They start chatting and find out they have a shared love for hiking. Another could be a story where they are both involved in a community project, like building a park, and they slowly fall in love while working together towards the common goal.
A fanfiction could be set in an alternate universe where Jacob and Rosalie are both students in a prestigious art school. Jacob is into more rugged and earthy forms of art, while Rosalie is drawn to the refined and classical styles. Their clash of artistic visions at first leads to rivalry, but eventually they inspire each other to create new and unique art forms.
One idea could be that the baby has a special power. For example, it might be able to communicate with animals in a way that surprises everyone in the family. Another plot could revolve around the challenges of raising a half - vampire baby, like finding suitable food sources that won't harm the baby or its development.