Yahya related to me from Malik that he had heard that A'isha, the wife of the Prophet ﷺ used to pray in a shift and head-covering.  

أَنَّ عَائِشَةَ زَوْجَ النَّبِيِّ ﷺ كَانَتْ تُصَلِّي فِي الدِّرْعِ وَالْخِمَارِ  

Yahya related to me from Malik from Muhammad ibn Zayd ibn Qunfudh that his mother asked Umm Salama, the wife of the Prophet ﷺ "What clothes can a woman wear in prayer?" She said, "She can pray in a shift that reaches down and covers the top of her feet."  

أَنَّهَا سَأَلَتْ أُمَّ سَلَمَةَ زَوْجَ النَّبِيِّ ﷺ مَاذَا تُصَلِّي فِيهِ الْمَرْأَةُ مِنَ الثِّيَابِ فَقَالَتْ تُصَلِّي فِي الْخِمَارِ وَالدِّرْعِ السَّابِغِ إِذَا غَيَّبَ ظُهُورَ قَدَمَيْهَا  

Yahya related to me from Malik from a reliable source from Bukayr ibn Abdullah ibn al-Ashajj from Busr ibn Said that when Ubaydullah ibn al-Aswad al-Khawlani was in the room of Maimuna, the wife of the Prophet ﷺ she used to pray in a shift and head-covering, without a waist-wrapper.  

عَنْ عُبَيْدِ اللَّهِ بْنِ الأَسْوَدِ الْخَوْلاَنِيِّ وَكَانَ فِي حَجْرِ مَيْمُونَةَ زَوْجِ النَّبِيِّ ﷺ أَنَّ مَيْمُونَةَ كَانَتْ تُصَلِّي فِي الدِّرْعِ وَالْخِمَارِ لَيْسَ عَلَيْهَا إِزَارٌ  

Yahya related to me from Malik from Hisham ibn Urwa from his father that a woman asked him for a decision, saying, "Waist-wrappers are painful to me. Can I pray in a shift and head-covering?" He replied, "Yes, if the shift is long."  

فَقَالَتْ إِنَّ الْمِنْطَقَ يَشُقُّ عَلَىَّ أَفَأُصَلِّي فِي دِرْعٍ وَخِمَارٍ فَقَالَ نَعَمْ إِذَا كَانَ الدِّرْعُ سَابِغًا