Her relationship with Bella would likely become more complex. As a vampire, she would have different needs and instincts. She might be more protective of Bella in a way that Bella doesn't understand at first. For example, she could sense danger towards Bella that a human wouldn't notice. But at the same time, Bella might be a bit afraid of her sister's new vampire nature, which could create some tension between them.
Well, at first, Bella's sister as a vampire might be over - protective of Bella. She would see Bella as fragile compared to her new vampiric self. However, as time goes on, Bella might start to resent her sister's over - protectiveness. On the other hand, the sister might start to feel left out as Bella continues her life with the Cullens. Their relationship could also be affected by the fact that the sister has to hide her true nature from most humans, and Bella has to keep that secret too. This could lead to a lot of secrets and lies between them, straining their relationship.
At first, their relationship might become strained. Bella's sister would have to keep her new identity a secret from Bella, which could create distance. But once Bella finds out, they could become closer as Bella tries to understand what her sister is going through. Bella might be more protective of her sister now that she's in a more dangerous world.
The sister could have a big impact. Suppose she has a gift of reading minds like Edward. She might be able to tell if Edward has any hidden motives towards Bella. If she senses something wrong, she'll surely try to break them up. But if she approves of Edward, she could actually be a great confidante for both of them, and help them communicate better when they have misunderstandings.
It would become more intense and complex. Jacob would be very protective, his werewolf instincts kicking in fully. He'd be constantly worried about Bella and the baby's safety.
Well, they would become even closer as they are about to be parents. Edward would be extremely protective of Bella, not just because she's his love but also because she's carrying their child.
If Demetri and Bella had a relationship, it would surely create a rift between the Cullens and the Volturi. The Cullens would be very protective of Bella and not trust Demetri easily. The Volturi, on the other hand, might see this as a threat or an opportunity depending on how they perceive Demetri's actions.
With Edward, their relationship would be different. They'd be more equal in terms of strength and power. No longer would Edward need to constantly protect Bella. Instead, they could fight side by side against their enemies. Their relationship might also have a new dynamic of competition, as they both explore their new vampiric abilities.
Well, at first, the Cullens might be more suspicious of Bella since she's related to James. But as they get to know her better, they might see that she's different from her brother.
It also makes her more patient. Vampire children, or even adult vampires she might be mothering in the fanfiction, can be difficult to understand and manage. Bella has to learn to be patient with their different ways of thinking and behaving. For example, if they don't understand human emotions like love in the same way, she has to patiently explain it to them.
Their relationship would likely become more intense. They would have a new bond through the baby. Edward would be even more protective of Bella, not just because he loves her, but also because she's carrying their child.
The baby sister in fanfiction could also have special abilities. Maybe she has a latent psychic ability that she discovers as she grows up. Bella, with her knowledge of the supernatural, could help her sister understand and control these powers. This would create a strong bond between them, different from a typical sister relationship, as they navigate the challenges of these unique abilities together.