Is the prayer of one who forgot to remove nail polish before Wudu valid, and is she required to repeat it?

For ablution (wudu') to be valid, anything that prevents water from reaching the skin, such as oils, nail polish, or wax, must be removed. Otherwise, the prayer is invalid. Wudu' is not valid if there is anything, whether little or much, that prevents water from reaching the limb. However, if it is a trace of henna or a fluid oil that does not prevent water from reaching the skin, wudu' performed with it is valid.

If one prayed while having something that prevents water from reaching the skin, out of forgetfulness, the sin is lifted from them, but they must repeat their ablution and prayer. This is based on the narration by Umar ibn al-Khattab (may Allah be pleased with him) that a man performed ablution and left a spot the size of a fingernail on his foot. The Prophet (peace be upon him) commanded him to perfect his ablution. So, he returned, then prayed.

If one forgets to wash a limb or part of it, and this occurs during wudu' or immediately after, before the limbs dry, they only need to wash what they forgot and what comes after it. However, if the limbs have dried, or if this occurs during prayer or after it, then one must restart the entire ablution and repeat the prayer.