Qadha of Esha Salaah if a woman's period ends before fajr

Q:

1. A woman is on her period. She goes to sleep at night but when she wakes up at fajr time, she realises that she must have become taahir during the night since there is no trace of blood. Does she have to make qadaa of the isha prayers? 

2. Would it have been necessary for her to set her alarm clock to wake her up before the end of isha time/start of fajr time, to check whether the period had finished at night, in which case she would avoid it becoming qada?

A: 

1. Yes.

2. As a precaution, it would have been better to do this.

And Allah Ta'ala (الله تعالى) knows best.

Answered by:

Mufti Ebrahim Salejee (Isipingo Beach)