Is the family religiously responsible for a sister who openly commits fornication and prostitution, and refuses to return and live with them? And are they obligated to support her financially despite her behavior and refusal to repent? What is the religiously lawful solution for dealing with her?

These actions are dangerous, and the sister is in great peril. We advise you to supplicate for her, especially from the parents, for the Prophet, peace and blessings be upon him, said: "Three supplications are answered without a doubt: the supplication of the oppressed, the supplication of the traveler, and the supplication of a parent for their child." It is obligatory to offer her advice in a kind, gentle, and lenient manner, for Allah Almighty says: "Invite to the way of your Lord with wisdom and good instruction," and the Prophet, peace and blessings be upon him, said: "Indeed, Allah is gentle and loves gentleness in all matters." If she does not benefit from the advice, then she should be boycotted if there is hope that boycotting will be beneficial. Her guardian is responsible for her and must be firm with her and restrain her, for Allah Almighty says: "O you who have believed, protect yourselves and your families from a Fire," and the Prophet, peace and blessings be upon him, said: "All of you are shepherds, and all of you are responsible for your flock."