What can be done about a sister who is immodestly dressed and addicted to watching TV and listening to music, and who refuses advice, while the mother asks that she be left alone, claiming that God is the Guide?

A Muslim is obligated to offer advice and invite to Allah, but the guidance of creation is in Allah's hands. Therefore, one must continue to invite the sister with wisdom and good counsel, endear oneself to her with gifts, gentle words, and kindness, supplicate for her, and seek assistance from pious sisters and female relatives to advise her. One should not pay attention to what people say, for caring for the Creator takes precedence over caring for the created.

The responsibility of reforming the sister falls upon her guardian, the father, who must take charge of his daughter and curb her actions that violate the Sharia (definition), by preventing her from associating with unsuitable companions, monitoring her entry and exit times, limiting expenses that could lead to her corruption, and other methods of reform.