What is the ruling on one who broke her fast in Ramadan, thinking that she had menstruated, then it became clear to her that she had not been menstruating; does she only have to make up the missed days (qada') or both make up the missed days (qada') and offer expiation (kaffara)?

It is impermissible to break the fast during the daytime in Ramadan except after verifying the existence of a valid excuse that permits it. And whoever intentionally breaks the fast by means other than intercourse is only required to make up the missed day (qada') and repent. As for whoever intentionally breaks the fast by means of intercourse, he is required to make up the missed day (qada') and offer expiation (kaffarah). Exemption from the expiation (kaffarah) applies to whoever broke the fast out of ignorance or misinterpretation; in such cases, only making up the missed day (qada') is required.