What is the ruling on prayer for a woman who miscarried a fetus after three months (90) days?

If blood appears with a miscarriage after the fetus has been formed, it is considered nifas (post-natal bleeding) blood, which prohibits prayer and fasting. The duration of fetal formation is after 81 days. Since the miscarriage occurred after ninety days, the blood is nifas blood. She must therefore refrain from praying and fasting until the bleeding stops or until she completes forty days.