How can a sister afflicted with burns, who is unable to use water or go to the restroom, and who cannot stand, bow, or prostrate, purify herself to perform prayer?

The sick person must fulfill the conditions, pillars, and obligations of prayer to the best of their ability. Whatever they are unable to do, or what causes them unbearable hardship, is waived for them. If they can use water for some limbs but not others, they should use it for the parts they can wash and perform tayammum (dry ablution) for the limb they cannot wash. If they are completely unable to use water, then tayammum suffices. If they are also unable to perform tayammum, they should pray the prayer of one who has lost both means of purification (i.e., without wudu or tayammum), and they are not required to repeat it.

They should limit their prayer to the obligatory acts and duties, so they should not recite more than Al-Fatihah, and it is sufficient to have tranquility and one glorification (tasbeeh) in bowing (ruku’) and prostration (sujud). If they are unable to stand, bow, or prostrate, they should pray sitting, and indicate bowing and prostration with gestures, making their prostration lower than their bowing. They should not place a pillow to prostrate on.