Is a son's insistence on waking his father, who is late for Fajr prayer due to oversleeping and refuses to be woken, claiming that a sleeping person is excused and that sleep overwhelms him, considered disobedience and a sin? And is the son's urging his father to perform Fajr prayer in congregation at the mosque after waking up considered exceeding the bounds of sin?

There is no harm in waking your father for prayer; rather, it is a form of filial piety, provided that wisdom and good admonition are observed. The Prophet, peace and blessings be upon him, woke Aisha for Witr prayer. The jurists have stipulated the desirability of waking a sleeper for prayer, and some of them consider it obligatory, as the impediment for a sleeper is quickly removed, and he is like one who is heedless, and alerting the heedless is obligatory.

It is also obligatory to advise the sister who abandons prayer, for abandoning prayer is a grave danger and an act of disbelief.