What are the consequences for a person who gave cold water to his young sister, who had no immunity and was suffering from influenza, which led to a deterioration of her health and her death several days later?

Enabling a young girl to drink cold water, knowing it is harmful, incurs sin and necessitates repentance. However, ruling this act as accidental killing, requiring blood money (diyah) and expiation (kaffarah), depends on verifying that the cause of death was the illness resulting from drinking the cold water. It is advisable to consult scholars in the country where the incident occurred to ascertain the cause of death.