Must a woman in postpartum bleeding (nifas) fast Ramadan if she completes forty days but is still in her nifas period and has not yet become pure?

Scholars have differed regarding the maximum duration of nifas (postpartum bleeding). The majority of scholars hold that it is forty days from childbirth. For a woman whose bleeding continues for more than forty days: if it coincides with her regular menstrual cycle, then it is menstruation (hayd); if it does not coincide with it, then it is irregular bleeding (istihada). In this case, she performs ghusl (ritual bath) after the forty days, observes fasting, performs prayers, and is considered pure.