It could be a vampire - related illness, like some reaction to a new type of venom.
Perhaps she caught a cold from being out in the rain too long. In the world of fanfiction, it could also be some sort of magic - induced sickness if there are magical elements involved in the story.
In some fanfictions, the cause could be a curse. There could be an old enemy of the village or someone with a vendetta against Naruto who placed a curse on him. This curse could be slowly draining his life force, causing him to become sick. Or, it could be related to the tailed beast inside him. Maybe there was some imbalance in the chakra of the Nine - Tails that was affecting Naruto's health. It's also possible that he caught a strange and rare disease from an unknown source during one of his travels to a far - off land.
In 'alice and bella fanfic', Alice is often depicted as very perceptive. She can foresee things, which gives her an edge in guiding Bella. Bella, on the other hand, is usually seen as brave. For example, in many fanfics, when they face danger together, Bella doesn't shy away. She stands her ground.
Alice might bring her warm soup and herbal tea. She could also read to Bella to keep her entertained while she's sick.
Friendship is a common theme. Many fanfictions explore the strong bond between Bella and Alice, how they support each other through various challenges in the Twilight world.
In these fanfics, the character development of both Bella and Alice is crucial. As Bella becomes a demigod, her personality may change or she may grow in certain ways. Alice also has to adapt to this new Bella. Also, the fanfics often have some sort of conflict. It could be an external conflict like other demigods or mythical creatures causing trouble, or an internal conflict within Bella as she tries to come to terms with her new identity.
I'm not sure specifically what Alice's claim is without reading the particular Bella fanfiction. It could be anything from a claim about Bella's true nature, a claim regarding a relationship in the story, or a claim about some hidden power or secret.
One characteristic is the exploration of their unique relationship. In many 'bella alice fanfiction', their friendship or sister - like bond is deepened and expanded. For example, they might share secrets or have adventures that only they can experience together.
One popular 'alice x bella fanfiction' might be those that explore their friendship in a new light. For example, a story could focus on how Alice helps Bella adjust to the vampire world in a more humorous way than in the original books. Maybe Alice takes Bella on a shopping spree through the vampire fashion world, which is full of unique and stylish outfits that are both practical for their super - fast movements and aesthetically pleasing.
Perhaps it's about Bella's transformation. Alice may have her own ideas about when and how Bella should be turned into a vampire. Bella, on the other hand, has her own desires and fears regarding the transformation. Their disagreements on this crucial aspect of Bella's life in the vampire world could result in a fight.
It could be that Alice accidentally touches Bella's hand during a class activity, which leads to a moment of shared confusion and then perhaps a new friendship starts to form as they exchange glances and small smiles.