Lochia - Nifas
Question : Is prayers obligatory while a woman is bleeding due to a miscarriage?
Answer : If the miscarried fetus was recognized as a child:
(a) If she has a habit of duration, then it is obligatory not to offer the prayers and not to have sexual intercourse with her husband for the number of days that corresponds to her menstruation period. If she continues to see blood after this period, then as an obligatory precaution she should do the same for a further day. She may continue to do so until the completion of the ten days. The remaining period of discharge is considered to be as Istihadha.
(b) If she does not a habit of duration, she should observe the above mentioned rulings for ten days. The remaining period of discharge is considered to be as Istihadha, and based on an obligatory precaution she should observe the rules of the woman during lochia (Nifas) for the completion of eighteen days.

If the miscarried fetus was not recognized as a child, like if it is a clot or lump of flesh, then based on an obligatory precaution she should offer the prayers based on the appropriate level of Istihadha and refrain from performing what is prohibited on the woman during lochia (Nifas).
Lochia - Nifas
Question : How many days after giving birth should I start praying? And how should I be showering after that? After how many days from the birth date can I and my husband retain our sexual life?
Answer : If a woman has a habit of duration, she should observe the rules for women during their menstrual period for the same number of day as the days of the menstruation period, so she should not perform her prayers and not have sex with her husband. If she continues to see blood after this period, then as an obligatory precaution she should do the same for a further day. She may continue to do so until the completion of the ten days. The remaining period of discharge is considered to be as Istihadha.

If she does not a habit of duration, she should observe the above-mentioned rulings for ten days. The remaining period of discharge is considered to be as Istihadha, and based on an obligatory precaution she should observe the prohibitions of the woman during lochia (Nifas) and act upon the rules of Istihadha for the completion of eighteen days.
ghusal
Question : I had my child and I was told that I have to wait for 40 days before taking the Nifas ghusl, and I cannot pray, fast ,etc during that time. Is this true?
Answer : The duration of Nifas is the same as that of the regular monthly period, which cannot be more than ten days, and does not last for forty days. During the time of Nifas, all the rules that apply to the woman in menstruation applies to her here.