What should a daughter who is ill with epilepsy—taking medication every 12 hours, and has missed 4 Ramadans—do, given that fasting takes 15 hours, while the nighttime period is 9 hours? And is she obligated to fast future Ramadans?

Her fasting in the coming Ramadan (definition) depends on the opinion of trusted doctors. If they say that spaced doses will not harm her, then she must fast. But if they say it will harm her, then she may break her fast and must make up the days after her recovery, according to the Almighty’s saying: "And whoever is ill or on a journey - then an equal number of other days." So, if she recovers, she should make up the missed fasts. If she is able to fast on short days without harming the duration of the doses, then she must do so.