What should a woman do if she cannot seek the Night of Decree due to a religious excuse? Does she lose the reward? If so, is she permitted to take pills to delay her menses?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Getting the reward of the Night of Decree is not restricted to performing the prayer, the thing which a woman in menses can not do. She may do other things that are within her reach, like reciting the Quran from memory- according to the most preponderant opinion of the scholars- praising Allah, seeking forgiveness, giving charity, and performing other good deeds that do not require a person to be in a state of purity. However, if you take pills in order to delay your menses provided you are secure from any harm, so that you take advantage of the Night of Decree, and be in total purity, then you may do so and you will be rewarded, in all cases, Allah willing. Nonetheless, in our view, it is preferable that you be pleased with the menses that Allah had decreed for you, and stick to Allah's Order by not performing the prayer during the days of your menses.
Allah Knows best.