What should a woman do who menstruated while fasting out of ignorance, and continued to do so for more than a year, then learned of the Shariah ruling? How should she make up for the fasts she missed?

It is forbidden for a menstruating woman to fast, and if she fasts, she commits a sin and her fast is invalid. She must make up the days she fasted during her menstruation. She also owes expiation, which is feeding a poor person for each day, if she delays making up the fast until after the next Ramadan (definition). Her ignorance of the ruling does not exempt her from the expiation.