Is it permissible to pay a ransom (fidyah) for seven days of missed Ramadan fasts due to migraines and work-related exhaustion?

As long as the questioner (sister) is able to fast, feeding the poor does not suffice for making up the fasts, as it is not permissible to resort to feeding the poor instead of making up the fasts except in the case of a chronic illness from which recovery is not usually expected, or in the case of old age where a person is unable to fast. If fasting is difficult for her, she can postpone it to a time when she is able to fast, such as winter. It is worth noting that drinking painkillers during the day invalidates the fast.