Alice could be a supporting character. Given her ability to see the future in the Twilight series, she could offer insights or warnings related to the baby's future. Also, Renesmee could play a role. Since she has her own unique situation in the Twilight world, she might be able to relate to the baby in some ways and offer her own form of support.
Jacob's father could be a supporting character. He could pass on his wisdom about family and fatherhood to Jacob. And some of the other vampires who are more friendly towards Bella, like Carlisle, might also be involved. They could provide medical knowledge or just general support as the baby grows up in this supernatural - filled world.
Charlie, Bella's father, would probably be a significant supporting character. He might be initially shocked but then come around to support Bella and Jacob in raising the baby. The wolf pack could also be important. They might offer their protection and guidance to Jacob as he becomes a father.
Obviously, Jacob and Bella are the main characters as it's in the title. They are the ones having a baby. But there could also be other important characters like their friends from the Twilight world, such as the Cullens who might play a role in the baby's life, either as allies or with some kind of conflict.
The main characters are Jacob and Bella. Jacob is a werewolf and Bella is a human who has a complex relationship with the vampire world. In the context of this baby fanfiction, they are the parents of the baby, so their actions and decisions will be centered around the well - being of their child.
Of course, the baby is also an important character in a way. Although it may not be able to communicate much at first, it will influence the actions and decisions of Bella and Jacob. Their families and friends, like the Cullens or the other members of Jacob's pack, could also be considered secondary characters as they will interact with Bella, Jacob and the baby in different ways.
Alice could be a supporting character. She might have visions about Bella's pregnancy and the future of the baby. Jacob could also be involved, perhaps initially being angry or concerned about Bella's situation with Aro. Carlisle could be another one, as his medical knowledge as a vampire doctor could be useful in dealing with Bella's pregnancy.
Bella is surely a main character. Since she's pregnant, her journey of dealing with the pregnancy, her emotions, and her future plans are key. Jacob, despite leaving, will still be important as his departure sets the story in motion. There may also be other characters like Bella's family or friends from the Twilight series, such as Charlie or Alice. They could be involved in Bella's life during this time, providing support or causing additional drama.
Bella herself could also be a significant character in this fanfiction. Her relationship with Jacob and her sister would be crucial. Her reactions to any potential relationship between Jacob and her sister could drive the story forward. Also, other characters from the Twilight series like Edward might make appearances, especially if they are involved in the overarching story related to Bella.
There might be a kind - hearted doctor in the 'baby bella gets sick fanfiction'. The doctor would examine Baby Bella carefully, give accurate diagnoses and prescribe the right medicine. Also, her best friend could be a character. Her friend might visit her often and bring her favorite toys or books to make her hospital stay or time of being sick at home more bearable.
There could also be other characters from the Twilight series involved. For example, the members of Jacob's wolf pack might play a role. They could be trying to mediate between Jacob and Bella, or they might side with Jacob, adding more tension to the story.
Obviously, the Cullens would be the main characters. Carlisle, as the patriarch, would play a crucial role in raising Bella. Esme would be like a mother figure to her. Edward would also be important, his relationship with Bella evolving from something different than in the original story. And of course, Bella herself is a central character.
The main characters are obviously Bella and Jacob. Since it's about them having a family, they would be central to the story.