Covering the ʿawrah is a condition for the validity of prayer, and for a woman the Prophet ﷺ said: "Allah does not accept the prayer of a woman who has reached puberty unless she wears a khimār (head-covering)" (Sunan Abi Dawud 641, sahih). So even praying alone she covers her whole body — including hair, neck, and ears — in clothing that is neither see-through nor so tight that it describes her limbs. The face is uncovered in prayer by agreement; regarding the hands and feet there is legitimate ikhtilāf — the Ḥanafīs excuse both, while the Ḥanbalīs count them as ʿawrah — so covering the feet is the safer course. Note that this is the ʿawrah of ṣalāh specifically; what she covers in front of non-mahram men outside is a separate and broader matter (Quran 24:31).
Q&A · Women in Islam
What must a woman cover when she prays alone at home?
Evidence — the daleel
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.