What must a woman do to make up for days of Ramadan that she missed due to a legitimate Shar'i excuse, then she was ignorant of the obligation to make them up, and the matter escalated to a chronic illness that prevents her from fasting, while her husband prevents her from feeding the poor with cooked food?

If the inability to fast is temporary, then making up the fast (qada') is obligatory without continuity, and one can choose to do it in winter. There is no expiation (kaffara) required for delaying the make-up fast, as you are excused due to ignorance.

However, if the inability is continuous, then a ransom (fidyah (definition)) is obligatory, which is feeding one poor person one mudd of food for each day, estimated at approximately 700 grams. This feeding should be done by giving uncooked food to the poor in their homes.

As for prayer, there is no obligation to make up missed prayers due to ignorance of the correct way to pray, based on the saying of Ibn Taymiyyah that the ignorant person is excused and is not required to repeat them. However, it is now obligatory to learn the rulings of the religion.