My wife had a miscarriage in her second month of pregnancy, when should she perform the prayer?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

When a woman has a miscarriage and the foetus took human form, then the blood that she has is post partum bleedings, so she should not perform the prayer until the blood completely stops, or after the elapse of forty days. Some scholars said that the embryo does not take human form until eighty one days elapse. Since the miscarriage occurred in the second month, if there is nothing which proves that the embryo took human form, like having a head, hands or feet, then the blood discharges are discharges outside the monthly periods and the woman should not abandon praying or fasting. However, if these discharges are continuous, she should be on the safe side and perform ablution after the beginning of the time for every prayer, and provided that these discharges do not have the characteristics of the monthly menses, and they do not coincide with the time of her monthly periods, as in this case they are menses. 

Allaah Knows best.