Does the fast of this day count, or is a make-up required, if a woman intended to fast in Ramadan before Fajr, believing that her menstrual bleeding had ceased, and indeed no blood appeared during the day, and she performed ghusl before Maghrib?

If a woman sees the sign of purity (white discharge or dryness) before Fajr, and she fasts with an intention made during the night, her fast is valid. However, she is mistaken for not performing ghusl and praying on time, and she must make up these prayers after performing ghusl. But if she does not see the sign of purity before Fajr, her fast is invalid, and she must make it up, because purity from menstruation is a condition for the validity of the fast from the beginning of the day until its end.