Is it obligatory to make up the fast and offer expiation for someone who fasted incorrectly during Ramadan due to ignorance of the ruling, then learned about the necessity of making it up and delayed it until after the following Ramadan, and is it permissible to delay the expiation if feeding is impossible due to war?

If a woman performs ghusl (ritual bath) and fasts after the cessation of her menstruation, she is not required to make up for the days of purity on which she fasted. Her fast is valid even if she has not performed ghusl, because ghusl from menstruation is not a condition for the validity of the fast. However, she must make up only the days of menstruation. If she fasted while menstruating, her fast is invalid and she must make it up. As for the prayers she performed after purification from menstruation without performing ghusl, there is a difference of opinion regarding the necessity of making them up. Since she has made them up, praise be to Allah. If she delayed making up some days until after the following Ramadan due to ignorance of the ruling, she is not obligated to pay expiation (kaffarah). It is advisable to strive against obsessive thoughts (waswas) and not give in to them.