Do the prayers the questioner missed because she thought her menstruation was continuing, when in reality she might have been pure, necessitate a make-up (qada')?

If a woman doubts her purification from menstruation, the default is that the menstruation persists until she is certain of purification. If she becomes certain that her discharges were normal moisture and not menses, then there is nothing upon her, because the default is that she had not yet ceased menstruating. However, if she becomes certain that she abandoned prayer, thinking she was menstruating, there is a difference of opinion among scholars regarding the obligation to make up those prayers. The more cautious approach is to make them up to absolve oneself of responsibility.