The baby itself could be a major factor in what happens next. It could have unique abilities that no one expected. Maybe it has the power to communicate with Bella in some way while still in the womb. This could lead to Bella having some sort of premonitions or knowledge about how to protect it and what the future holds for them all.
The Cullen family might also get involved in different ways. Some of them could be sympathetic towards Bella and offer their help, while others might be more hesitant due to the implications of a half - vampire baby. Esme, for example, might be very motherly and try to take care of Bella, while Rosalie could have mixed feelings because of her own history with not being able to have children.
Well, it could be that Edward is homeless because of some dark turn of events. Bella's encounter with him might be the start of a new adventure. She might introduce him to her friends in the fanfiction world, like Jacob, and there could be some tension as Jacob may not trust this new 'homeless' Edward right away.
One possibility is that their relationship could face initial resistance. In many Twilight fanfictions, Bella's friends or family might be concerned about the age difference. They could try to keep them apart, creating drama and tension in the story.
One possibility is that Renesmee is simply curious. She might ask them what they are doing in a very innocent way. For example, if they are having a private moment, she could break the mood but also add a touch of humor to the situation as they quickly adjust to her presence.
Well, for one, the whole concept of their courtship would be different. Since Bella is now the vampire, she would be the one with the enhanced senses and abilities. She might be more forward in the relationship as she doesn't have the same insecurities as she did as a human. Edward, on the other hand, might be more hesitant and in awe of Bella's newfound power.
One possibility could be that Bella has to face the challenges of pregnancy alone. She might struggle with the physical and emotional changes while also dealing with the absence of Edward. The Cullen family could be in a dilemma about whether to support her or not, as Edward's departure might have left them with mixed feelings. And Bella could start to discover new powers or abilities within herself as she copes with the pregnancy, which could be a big part of the fanfiction plot.
In some fanfictions, if Edward leaves Bella, she might become stronger and more independent. She could focus on her own life, perhaps pursue her studies or hobbies more intently. For example, she might finally decide to travel the world and discover new things on her own.
One idea could be that Bella has to face the challenges of being a single mother in the vampire - human world. She might struggle to keep her baby safe from the Volturi.
In such a fanfiction scenario, perhaps their relationship would take on a very different dynamic. Since it's 1918, the social and cultural context was vastly different from the original story's setting. They might face different challenges, like dealing with the aftermath of World War I. Maybe Edward, being a vampire, would have to be more discreet in a time when superstitions were high and any odd behavior could draw unwanted attention.
One possible outcome is that Edward will use his mob influence to protect Bella's niece from any threats. Since he's a mob boss, he has power and resources at his disposal. Maybe he'll give her a life of luxury and safety she never had before.
One possible reason could be that he suddenly realizes he's putting Bella in too much danger. In the Twilight universe, Bella's life is constantly at risk because of Edward's vampire world. Maybe in the fanfiction, he decides at the last minute that he can't bear to see her hurt because of him.