Is the fasting of a woman in nifas (postpartum bleeding) valid if she became pure after five days, then the blood returned, and she fasted the days following her purity?

If a woman experiencing post-natal bleeding (nifās) purifies after five days and then fasts, and then the bleeding returns, there are two possibilities:

1. The blood returns after forty days from the beginning of nifās. This is menstruation, and fasting is not valid with it.

2. The blood returns before forty days. In this case, specialized fatwas should be consulted.