Is it permissible to encourage one's sister to seek divorce and separation from her husband, especially after repeated problems, the husband's transgressions against her and her children, and his threat to marry another, knowing that he has previously divorced her twice, while taking into account that the sister will bear the consequences of this divorce?

Reconciliation and bringing the spouses together as much as possible is best. It is not permissible to encourage a wife to leave her husband, as this constitutes forbidden incitement (takhbib). Rather, the wife should be advised to obey her husband, not to leave the house except with his permission, and not to allow anyone into his home except with his permission. In the event of divorce, custody belongs to the mother unless she remarries or there is an impediment, and housing for the irrevocably divorced woman (mutallaqah ba'inah) is provided if she is pregnant, until she gives birth.