A woman's ignorance of the ruling on making up for the missed days of fasting, but after knowing, she started to fast the White Days

Q: My mother is about 65 years old. Since she started her monthly period until she reached menopause, she did not know the ruling on making up for missed days of fasting on which she had her monthly period and so on until she reached menopause. She has not made up her missed days of fasting. The average duration of her monthly period was four days. After she learnt that she must make up for her missed days of fasting approximately two years ago, she started to fast three days every month. Therefore, we ask Allah (Exalted be He) first and then Your Eminence to give us a detailed answer to this question.

A: Your mother must make up for her missed days of fasting in Ramadan starting from the time she reached puberty. In addition, she must also feed a Miskin (a needy person) for each day she missed which she delayed from one Ramadan to another if she is able to do this. If by fasting three days each month she intends to make up for the missed days of fasting, then these days are counted from her missed days, based on the Hadith of the Prophet (peace be upon him): The reward of deeds depends upon the intentions and every person will get the reward according to what he has intended. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.