What should a woman do who began making up for the days of Ramadan she missed at the age of forty, while she was unaware of the obligation to make them up since her youth, and the number of days she needs to make up is approximately 160 days?

The sister who asked the question is obliged to make up the days she missed, as it is a debt upon her, for the Prophet, peace and blessings be upon him, said: "Allah's debt is more worthy of being fulfilled." She must make them up immediately, to the best of her ability without harm. If she has already made them up, then praise be to Allah. Otherwise, she should hasten to make them up, while seeking forgiveness for her negligence in seeking knowledge. There is no fidyah (definition) (expiation) upon her for delaying the making up of the fasts due to her ignorance of the prohibition of delay.