What is the ruling on the prayer of a woman who has become pure from nifas (postnatal bleeding), then for two months menstruation did not come due to breastfeeding, and then she saw dark, intermittent discharge?

Yellowish or brownish discharge, or dark fluid that exits a woman and is not connected to menstrual blood or postpartum bleeding, is not considered menses. Prayer and fasting are permissible with it. The proof for this is the saying of Umm Atiyyah (may Allah be pleased with her): "We did not consider yellowish or brownish discharge after purification to be anything." Therefore, a woman must perform her prayers and do what is permissible for women who are in a state of purity.