Period of nifaas for a woman who did not bleed for her previous pregnancy
Q: I wanted to know that if a woman had 15 days nifaas in her first childbirth and in the second not a drop of blood came but the in the third childbirth she had 50 days bleeding. What will be her nifaas? 15 days or does she have to pray 40 days qadha namaz as her previous nifaas was nill?