Sango could also take care of Kagome. As a strong and kind - hearted woman, she would know how to nurse Kagome back to health. She might use her knowledge of herbs and remedies to make Kagome feel better. Plus, she would offer emotional support to Kagome during her illness.
Kilala, Sango's cat - demon companion, could also play a role in taking care of Kagome. Kilala could provide warmth to Kagome when she is shivering from the fever. And in a more magical sense, Kilala's presence might have some sort of calming effect on Kagome, which could aid in her recovery.
His teammates, Sasuke and Sakura, would surely be involved. Sasuke, although he may not show it as much, still cares about Naruto. He would keep an eye on Naruto's condition, and if there was any sign of danger, he would be ready to protect him. Sakura would be more hands - on with the medical care, checking his temperature, giving him medicine, and making sure he rests properly.
In the fanfiction, it could be that Sailor Chibi Moon comes to take care of Sailor Moon. Since she looks up to Sailor Moon so much, she would do everything she can. She might even use her own little powers in a unique way to try and make Sailor Moon feel better, like creating a warm and cozy environment around her bed.
Padmé could also be involved. She is known for her compassion. She might use her resources to get the best medical help for Ahsoka. She could bring in the best doctors in the galaxy or some special remedies from Naboo.
Alfred would probably be the first one to take care of him. He's always there for Batman.
Her friends could take care of her. For instance, Yuki might bring her some herbal tea that he made himself, believing it would help with her illness.
Thor could be one of the first to take care of Loki. Despite their differences, Thor still cares about his brother. He would use his strength to protect Loki from any threats while Loki is sick and might even search for rare remedies.
Gwen could also take care of Ben. As his cousin, she would be worried about him. She might use her magic to try and ease his symptoms or find a cure. She would probably make him some soup and keep him company while he's sick.
His best friend could be the one to take care of him. This friend would stay by his side, make sure he takes his medicine on time, and keep him company while he's sick.
Well, perhaps in the fanfiction, Kagome's sickness is a result of some dark magic. Her getting sick could be a part of an enemy's plan to stop her from interfering in their evil deeds. Her friends then have to not only deal with her illness but also figure out who is behind it all and stop them before it's too late.
Seth could be the one to help her. As her brother, he would be very concerned and might use his own knowledge of Fablehaven and its secrets to try and find a cure. He could also enlist the help of some of the friendly magical creatures they've befriended, like the fairies or the satyrs.