Edward is almost always there. Since he's such a central figure in Bella's life as a human and vampire in the original story, he would likely play a big role in the fanfiction too. He might be the one guiding Bella through her new vampire life.
One interesting plotline could be Bella's struggle to control her new vampire instincts while still maintaining her relationships with her human friends and family. For example, she might have a hard time being around them without revealing her new nature.
Her relationships with her human friends will surely be affected. They might be scared of her at first, or she might be afraid of hurting them. So she may start to distance herself from them.
Well, she might struggle with her newfound vampire nature. Maybe she has a hard time controlling her thirst for blood and accidentally attacks someone she cares about.
Often, there's a plotline centered around the baby's future. Will it be a normal vampire? A hybrid with unique powers? The fanfiction might explore how Bella and the others prepare for the baby's arrival, including things like finding a safe place to give birth. And there could be a plotline about the baby being a symbol of hope or a threat, depending on different characters' perspectives.
Well, she might struggle with her newfound vampiric nature. Maybe she would try to resist the urge to feed on humans, like Angel did. She could also find herself at odds with Buffy, who would be torn between protecting her sister and fighting the vampire she has become.
In a fanfic where Harry gets turned into a vampire, one thing that could occur is that he would be shunned by the wizarding community at first. They would see him as a threat. But he could also use his vampire powers to his advantage in fighting the dark forces. He might be able to use his enhanced senses to detect danger earlier. Also, his immortality could change his perspective on life and his long - term goals. He could become more isolated as he outlives his friends, or he could try to find a way to reverse the transformation.
It could lead to a whole new set of adventures and challenges for Dawn. Maybe she'd have to learn to control her vampire urges while still trying to maintain her relationships with friends and family.
His appearance would likely change. He could have paler skin, redder eyes perhaps. And his senses would be heightened. He would be able to smell blood from a distance, hear the faintest of sounds. Also, his speed would increase. He could move like a blur, which would be a huge advantage in many situations, like escaping from danger or chasing after someone or something.
Well, he might struggle with his newfound thirst for blood. He'd have to deal with the wizarding world's reaction, which would probably be a mix of fear and fascination. His friends might be torn between helping him and being scared of him.