What should I do about my sister who wears the hijab only when she goes out, uncovers her hair in front of my sisters' husbands and others, adorns herself inside and outside the house, listens to music, and keeps pictures of singers?

Strengthening faith, mending hearts, and perfecting prayer are the foremost priorities for rectifying deviations. For when the heart is sound, the entire body is sound. And prayer restrains from indecency and evil. The remembrance of Allah is a fortress against Satan, just as knowledge of the afterlife suppresses desires. It is recommended to have a daily program for teaching rulings, encouraging good deeds, and warning against evil, as well as providing good company, and reviewing the rulings regarding hijab (definition), listening to music, and images.