Muhammad bin Zayd al-Qurashi narrates from his mother that she asked Umm al-Mu'minin Umm Salamah (may Allah be pleased with her): In how many garments may a woman pray? She replied: She should pray in a large head-covering and a long shift that covers the tops of her feet.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3250