What must a woman do who broke her fast in Ramadan due to menstruation and does not know the number of days she missed years ago?

The cessation of menstrual bleeding is a condition for the obligation and validity of fasting. It is forbidden for a menstruating woman to fast, and she must make up the missed fasts. The prohibition of fasting for menstruating women and the obligation to make up the fasts are indicated by Prophetic hadiths; among them is the hadith (definition) of Abu Sa'id al-Khudri in al-Bukhari, and the hadith of 'A'isha in Muslim. Therefore, if the questioner fasted during her menstruation, she must repent and make up the days she fasted while menstruating, or the days she did not fast. If she stopped fasting altogether for years, she must make up a full month for each year, along with paying expiation for her negligence (feeding a poor person for each day) for delaying the makeup fasts without a valid excuse.