How is a valid, lawful divorce pronounced for a wife who experiences menstruation only after long and irregular periods, knowing that no divorce has yet been pronounced?

A Sunnah divorce is when a man divorces his wife with a single pronouncement during a period of purity (Tuhr) in which he has not had intercourse with her, and then leaves her until her iddah (waiting period) expires. If he has had intercourse with her, then he must wait until she menstruates and then becomes pure again, then he divorces her before touching her (having intercourse). The delay of menstruation does not affect this. It is permissible for a woman to take medication to induce menstruation so that the husband can divorce her with a Sunnah divorce. The idea of abstaining from intercourse with one's wife for four months has no basis. If the divorce or khul (dissolution of marriage initiated by the wife) is at the wife's request, then there is no harm in it even during menstruation, because the prohibition (of divorce during menstruation) is for the woman's right, and if she agrees to waive her right, the prohibition is removed.