Carlisle could be included. His wisdom and calm demeanor could be a great contrast to the passion of Bella and Edward's honeymoon. He could offer some medical or historical vampire knowledge that helps them understand something new about themselves or their situation. For instance, he might tell them about some old vampire honeymoon traditions that were practiced centuries ago.
Jacob could be an interesting addition. He might show up unexpectedly, and his presence could create some tension between Bella and Edward. His wolf nature could also interact in an interesting way with the vampire - dominated environment of their honeymoon. For example, he could sense some hidden danger on the island that the vampires are oblivious to.
Edward and Bella are the top ones. Their love story has a huge fan base, and in fanfiction, writers often delve deeper into their characters. Jacob also remains popular. Even though his relationship with Bella has changed, his loyalty to her and his role in the werewolf pack make him an interesting character to write about. Also, the Cullen family members like Alice are popular as they add more depth and mystery to the stories with their special abilities.
Also, some fanfictions might introduce new characters unique to the story. But overall, it's Bella and Edward's honeymoon, so they are the ones that drive the story forward. Their different natures, with Bella being mortal and Edward being immortal, create a lot of interesting dynamics during their honeymoon time, like how they deal with Bella's mortality and their future together.
One popular original character could be a new vampire who becomes a close friend to Bella and Edward. This character might have a tragic backstory that makes them interesting. For example, they were turned against their will and are now trying to find a new purpose in their undead life.
One idea could be exploring more of the island's secrets during their honeymoon. Maybe there are hidden caves with ancient vampire lore that Bella and Edward discover. Another could be focusing on how their relationship deepens in a more emotional and spiritual way, away from the chaos of their previous adventures.
Edward and Bella are the main characters. Edward, with his super strength, speed, and ability to read minds (except Bella's). Bella, who is now Edward's wife, is known for her strong will and her deep love for Edward. In the fanfiction about their honeymoon, we see how they interact and build their new life together as a married couple.
Alice is often a popular character. In high school fanfiction, she might use her ability to see the future to help Bella and Edward avoid potential problems, like a surprise attack from other vampires or getting caught by the school authorities doing something vampire - related.
Alice is often quite popular. She has the ability to see the future, which can add a lot of interesting twists to the story. For example, she might see a danger coming towards Bella and Edward and try to prevent it. Her quirky personality also makes her a favorite among fans.
One interesting plot could be Bella exploring her new vampire powers in more depth than in the original. For example, she discovers unique ways to use her speed and strength that no other vampire has thought of. Another plot might involve Edward and Bella facing a new threat to their family that is specific to their situation as a vampire - human - vampire family. It could be a new type of vampire with different abilities that challenges their way of life.
The main characters are likely Bella and Edward, as 'Breaking Dawn' is mainly about their story, and a honeymoon fanfic would probably center around them.
Renesmee is often a popular character. Writers like to explore her unique existence as a half - vampire, half - human. They might develop her character further, showing her growing up and dealing with the challenges of her dual nature.