Tinga Bella herself is of course extremely popular. She is the central figure and often the focus of most fanfictions. Her sidekick, if she has one, like a small magical creature that helps her, can also be a popular character. Another popular character could be her mentor, an older and wiser being who has taught her most of what she knows.
There are many animal characters. For instance, the zebra is one of the prominent characters. It has its own distinct personality and often gets involved in various adventures in the Tinga Tinga world.
Edward is still very popular. Since he and Bella are now both vampires, their relationship takes on new aspects that fans like to explore. Another popular character is Alice. Her ability to see the future could be really interesting in a story where Bella is a vampire. She could foresee events that involve Bella and help her avoid danger or make important decisions.
Bella is obviously one of the most popular. Since she is the main character in the original series, in fanfiction she often remains the central focus. Her relationships with the Cullens, especially Edward, are often explored in great depth.
I think Carlisle also has a certain popularity in Renesmee, Bella and Edward fanfiction. As the head of the Cullen family, his wisdom and his way of leading the family are often explored. And his relationship with Edward and how he influences Renesmee's upbringing can be a focus in some stories. Esme, too, can be popular as she represents the motherly figure in the family.
Alice Cullen can be a very popular character. Since she can see the future, in a 'reborn as bella swan' scenario, her interactions with Bella could be really different. Maybe she tries to guide Bella in a new way based on her visions. Also, Carlisle Cullen is popular. His father - figure role towards Bella might be explored further in these fanfictions.
One idea could be a time - travel plot. Tinga Bella could travel back in time to a key moment in her world's history and have to make choices that change the future. Another could be a crossover with another fictional universe, where she meets new characters and has to adapt to a different set of rules. Or perhaps a story where she loses her powers temporarily and has to rely on her wits and the help of her friends to overcome a powerful enemy.
In these crossovers, Bella Swan herself is often very popular. Her relationship with Edward in the Twilight series makes her an interesting character to transplant into the Vampire Diaries universe. Also, Damon Salvatore from Vampire Diaries is popular. His bad - boy charm and complex personality add a lot of drama to any fanfiction story.
The Cullen family members are also quite popular. For instance, Alice, with her ability to see the future, can be a key character in many fanfictions. Her visions could lead to all sorts of interesting plot twists, whether it's warning about a coming danger or seeing a new opportunity for the family.
Jacob might also be a popular character in some of these fanfictions. His relationship with Bella in the original series was complex, and in fanfiction, it can be further explored, even in the context of Bella and Edward's relationship, creating a sort of love triangle - like dynamic.
Bella is obviously one of the most popular characters as she is the central figure in the original 'Twilight' series and in this fanfiction as well. Her relationship with both the vampire and wolf elements is what drives much of the story.