Is the blood that came out of the pregnant wife in her second month due to a weak pregnancy considered lochial blood (nifas), or is she permitted to pray despite the bleeding, especially given that she underwent a D&C on 13 Shawwal 1425?

The blood discharged after a miscarriage that did not reach 81 days is not considered lochial blood (nifas). The blood discharged from the wife is considered irregular bleeding (dam fasad) and does not prevent her from doing what nifas prevents.