Is it permissible for a woman to pray and fast if her menstrual period exceeds the usual duration and becomes like a hemorrhage?

If the duration of menstruation exceeds its usual period, then she continues to consider it menstruation as long as the bleeding persists. Thus, she does not pray, nor does she fast, and it is not permissible for her husband to approach her, because menstruation can increase or decrease. However, if she purifies herself and performs ghusl, then sees yellowish or brownish discharge, it is not considered anything. So, she prays, fasts, and becomes permissible for her husband, based on the saying of Umm Atiyyah (may Allah be pleased with her): "We used not to consider yellowish or brownish discharge anything after purification."