Is it obligatory for a woman to cover her entire body during prayer, except for her face?

Question:
May Allah reward you and benefit the listeners with your knowledge. A woman from Taif, whose name is Nun-Fa-'Ayn, asks several questions. In the first one, she says: I have a nightgown that reaches below my ankles, but I do not pray the five obligatory prayers in it; rather, I sometimes pray the witr prayer in it while sleeping. Is my prayer valid?

Answer:
It is obligatory for a woman to cover her entire body in prayer, except for her face, if there are no non-mahram men present. If there are non-mahram men present, she must cover her entire body, including her face, in prayer, and nothing of her body should be visible, not from the legs, not from the hands, and not from any part of the body. Prayer in a covering that falls short of the ankles or part of the ankles is not valid; because in that case, she is not covering her 'awrah (part of the body that must be covered). Yes.