Perhaps the story could take a really dark turn. With Bella dead, the Volturi might see this as an opportunity to assert more control over the Cullens. They could come to Forks under the pretense of investigating Bella's death but really be there to intimidate the Cullens into following their strict vampire laws more closely. Meanwhile, Jacob could struggle with his own identity and his role in Bella's death. He might feel like he failed to protect her, and this could lead to him making some rash decisions in his werewolf form, endangering not only himself but also his pack.
Edward would be completely shattered. He might lose all sense of purpose and even consider ending his own existence. Jacob would be filled with anger and grief. He might blame Edward and the Cullens for not protecting Bella. Charlie would be heartbroken and would likely be in a state of shock for a long time.
One possible development could be that the relationship between Bella and Edward becomes even more complex. Edward might feel a stronger sense of protectiveness towards her. Also, it could lead to a rift between Bella and Jacob, as Jacob may not be able to handle the situation well. The Cullen family would also be greatly affected, having to deal with a pregnant human in their midst.
One possible plot development could be that his friends are left to pick up the pieces. They might struggle with grief and guilt, thinking they could have saved him. Another could be that Voldemort finally takes over completely without Harry to oppose him, leading to a dark reign over the wizarding world.
Perhaps the Cullen family has to deal with the shockwaves of Bella's death. They may face challenges from the vampire community as Renesmee is a unique being. Some vampires might see her as a threat or an abomination. The family would then have to protect Renesmee at all costs while also mourning Bella.
One possible plot development could be that Sasuke is in a life - threatening situation, perhaps against an extremely powerful enemy. Naruto sacrifices himself to give Sasuke a chance to escape or defeat the foe. This would likely lead to Sasuke being filled with guilt and regret, and might change his whole outlook on life.
Another direction could be that they focus on building a normal life within the vampire world. They might start a school for other vampires or hybrids, teaching them how to co - exist with humans. Edward could use his knowledge of music and literature, and Bella could share her experiences of being human - turned - vampire.
The other demigods at Camp Half - Blood would also be in chaos. Percy was like a leader to many of them. His death could lead to a lack of confidence among the younger demigods. Some might even start to question the protection of the gods. Zoe's survival could also lead to her taking on a more prominent role in guiding and protecting the demigods, which is a big change from her previous situation.
One possible plot development could be that Bella's job as an exotic dancer draws the attention of the vampires in Twilight. Maybe they are intrigued by her confidence and allure in this new role, which could lead to new and different interactions compared to the original story.
One common plot development could be the reactions of other characters. For example, Edward might be consumed by grief and guilt, feeling that he should have been able to prevent Bella's death. Another could be the future of the child. Maybe the Cullens have to figure out how to raise the half - vampire, half - human child without Bella. And also, there might be flashbacks in the fanfiction, showing Bella's life before the fateful childbirth and how she was looking forward to the baby's arrival.
One possible plot development could be that Voldemort fully regains his power without Harry as an obstacle. The wizarding world would be plunged into complete darkness. His friends, like Hermione and Ron, might go into a deep state of despair and then form a resistance group. They would try to find other ways to defeat Voldemort, perhaps by seeking out more powerful magical artifacts or uniting with some previously neutral magical creatures.