Another theme could be growth. As the story progresses, both Bella and Brian might grow as individuals, learning from their experiences together. For example, if they face a difficult situation like a natural disaster, they come out stronger on the other side. In many of these fanfictions, friendship is also a theme. They make new friends while going through different adventures, and these friendships also contribute to their growth.
Love and protection are also prevalent themes. Peter may be very protective of Bella, and Bella might have a deep love for her brother. This can be seen in the way they interact and the sacrifices they are willing to make for each other in the fanfiction stories.
One theme that might show up is protection. Eric could be very protective of Bella, or vice versa. It could also involve themes of acceptance, especially if their relationship is different from what others expect. For example, if they come from a different background or have unique abilities. There could also be themes related to growing up together and the shared experiences that shape their characters.
One common theme is family loyalty. Since they are sisters, the stories often explore how they stay loyal to each other no matter what. Another theme is the discovery of self. They might learn more about themselves through their relationship with each other. Also, there can be a theme of acceptance, as they accept each other's flaws and strengths within the sisterly bond.
One common theme is family dynamics. Since it's about Bella's sister, it often explores how the sister fits into the family structure, especially with Bella being so central in the original Twilight story. Another theme is love triangles. Just like in the original, but now with the sister involved in some way.
A common theme is the power of sisterhood. The stories often show how Bella and her wolf sister support each other through tough times.
One common theme is sisterly love and loyalty. These stories often show the twins supporting each other through thick and thin. For example, in many fanfictions, when one sister is in trouble, the other will go to great lengths to help.
One common theme is family loyalty. The sister often stands by Bella through all the strange events in Forks. Another theme is self - discovery. As the sister witnesses Bella's experiences, she also starts to learn more about herself.
Another common theme is the discovery of self - identity. The older sister, while protecting Bella, also discovers more about herself. She might find out that she has some hidden powers or abilities. And in the process of dealing with all the Twilight - related events, she learns more about who she really is and what her role is in this strange world.
One common theme is identity. Bella has to re - define who she is as Caius' sister instead of just being Edward's love interest. Another theme is family loyalty. She has to figure out where her loyalties lie between the Cullens and the Volturi.
Common themes include family unity. Since Bella is now part of their family, there's often a focus on how they all come together, support each other, or face challenges as a unit. Identity is also a theme. Bella's identity is now different as she is related to Jane and Alec, and she has to navigate that. And then there's the theme of acceptance. How do the other characters accept Bella as their sister? And how does Bella accept her new family situation? These are all things that are frequently explored in this type of fanfiction.