Is the prayer obligatory for a woman in postpartum bleeding if her menstrual period occurs twice in one month and she is breastfeeding?

If the first period ends and the woman sees one of the two signs of purity (the white discharge or dryness), then the second period comes after a period of no less than fifteen days (the minimum period of purity according to the majority of scholars), then this is a normal menstruation and she must refrain from prayer. However, if the second period comes after the first in less than fifteen days, then the blood is not menstruation but rather istihada (non-menstrual vaginal bleeding), and it is not obligatory to refrain from prayer or fasting.