May one wipe (apply masah) over headscarf while performing minor ablution?
Lexical meaning of masah is to remove the remnants on something by wiping over with hand. Accordingly, it is obligatory to touch the head with wet hand in order to apply masah on it. Therefore, applying masah over the things such as headscarf, bonnet, wig, etc. that will block wet hand’s touching head is not a valid way of wiping over the head (Ibnu’l-Humam, al-Fath, I, 159). However, women may perform masah in ablution by putting their hand under headscarf without removing it. Because Prophet Muhammad (saw) applied masah by putting his hand under his turban without removing it (Abu Dawud, Taharah, 57).
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS