May Allah reward you, our Shaykh. A woman had the time for Dhuhr prayer enter, but she became busy with some matters, and before the time ended, when she intended to pray, her period started. Should she make up the prayer when she becomes pure?

Yes. The correct opinion is that if a woman becomes pure,

and she caught enough time for one rak'ah,

she must make up the prayer, because the Prophet ﷺ said: Whoever catches one rak'ah of the prayer has caught the prayer.

She caught one rak'ah of its time, so she must

make up the Dhuhr prayer.