In the Name of Allaah, The Most Merciful, The Ever Merciful
What should a woman do if she cannot observe worship in the Night of Al-Qadr because she has an excuse justified by Sharee‘ah? Will she miss the reward? If she will, then is she permitted to take pills for delaying menstruation?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Observing worship in the Night of Al-Qadr is not restricted to praying. As menstruating women cannot pray, they can seek the Night of Al-Qadr as much as they can by, for example, reciting the Quran by heart, according to the preponderant opinion; praising Allaah; supplicating Him; seeking His forgiveness; giving charity; and doing righteous deeds that do not require purity from menses. It is permissible to take pills to delay menstruation to witness the Night of Al-Qadr, provided that women will be safe from harm, maintaining full purification. They will be rewarded, Allaah Willing, in all cases. However, we prefer that they are satisfied with the divine decree of having menses and comply with the divine command of not praying during the days of menstruation.

Allaah Knows best.