What is required of a woman who vowed to fast a specific day but did not fast it without an excuse? Is she only required to offer expiation (kaffarah), or also to make up (qada’) the fast, despite the time for it having passed?

Whoever vowed to fast on a specific or designated day and did not fast it without a valid excuse, is obligated to make up for it (qada') and offer expiation (kaffarah) similar to the expiation for breaking an oath. If they had a valid excuse, then there is a difference of opinion among scholars regarding it.