How can one deal with the nephews who watch movies and listen to music, given their mother's unresponsiveness to advice and their father's frequent absence, in order to help them abandon these practices?

We advise you to alert your brother to the importance of caring for his children and raising them according to the teachings of religion, for he is responsible for them on the Day of Judgment, as Allah Almighty says: "O you who have believed, protect yourselves and your families from a Fire" (At-Tahrim: 6). Ask him to urge his wife to take care of the children. We also advise you to draw closer to the children with gifts and kind words, and to seize every opportunity to advise them and teach them matters of their religion.