Is the wife sinful if her husband is unable to wake up for Fajr prayer, especially if he is in a state of major ritual impurity (junub) or tired, and is it permissible for her to abstain from him for the sake of prayer?

If a husband calls his wife to his bed, she must obey him, based on the Prophet's (peace and blessings be upon him) saying: "(If a man calls his wife to his bed and she refuses, and he spends the night angry with her, the angels curse her until morning)." If the husband then sleeps, the wife should wake him for Fajr prayer. If he does not wake up, the sin is on him, and the wife bears no blame for that. The wife is responsible for fulfilling her obligatory right, while the husband is responsible for his prayer and his negligence. Jurists have explicitly stated the permissibility of a husband approaching his wife at night, even if it leads to her delaying ghusl (ritual bath) until after the Fajr prayer due to her sluggishness. In such a case, he should instruct her to perform ghusl and pray. Accordingly, it is not permissible for the wife to refuse her husband, and she must wake him for prayer. There is no sin upon her if the husband is negligent and delays the prayer beyond its prescribed time.