What is the ruling on the prayer and fasting of a woman who performed ablution while unaware of the necessity to remove nail polish, and after becoming aware, could not find a remover, and continued in that state for a week?

Among the conditions for the validity of purification (taharah) is that water must touch the skin. If there is a barrier between them, such as oils, polish, or wax, the purification is invalid, and the prayer (salat) is nullified. The evidence for this is the Prophet's (peace be upon him) command to Abu Dharr (may Allah be pleased with him): "Then let your skin touch it, for that is better." Al-Shafi'i, Al-Nawawi, and the Permanent Committee have affirmed this meaning. Therefore, a woman must remove nail polish before performing ablution (wudu'), and she has no excuse for praying with an invalid purification. She must repeat the prayers she performed with that purification.