What is the ruling on an aunt hosting her friend's daughter, who is immodestly dressed, does not pray, and goes out late, despite being forbidden from doing so, under the pretext of the girl being an orphan and seeking refuge with her?

It is permissible to host the girl while advising her, enjoining good upon her, forbidding evil from her, and attempting to change her behavior, especially her abandonment of prayer. If that does not benefit, then it is better not to host her and to expel her from the house. The questioner has done her part by forbidding her aunt from hosting that woman if she insists on committing sins.