One popular 'dying girl hospital fanfiction' might be 'The Last Days in the Hospital'. It focuses on the emotional journey of a dying girl, her relationships with the hospital staff and other patients, and how she copes with her impending death.
There's a fanfiction called 'Hope in the Hospital Ward'. In this story, the dying girl discovers newfound strength and purpose while in the hospital. It shows her interactions with kind nurses and doctors who try to make her remaining days as comfortable as possible. It also delves into her dreams and hopes in the face of death.
Well, 'A Dying Girl's Hospital Diary' is another example. It's written in the form of a diary, from the perspective of the dying girl. It details her daily experiences in the hospital, from the pain she endures to the small moments of joy she finds. It also explores her thoughts about life, death, and the afterlife.