When does one pray the Repentance Prayer if the sin occurs during times when prayer is forbidden, or if the woman is menstruating?

The repentance prayer (Salat al-Tawbah) is among the prayers performed for a specific reason (min dhawat al-asbab), and it is permissible to perform it during the prohibited times. It is prescribed when its cause exists. However, in the case of a woman's legitimate excuse (i.e., menstruation or post-natal bleeding), the repentance prayer is not prescribed for her. It suffices for her to repent, seek forgiveness, and perform other good deeds, for "indeed, good deeds do away with evil deeds."