Sahih al-Bukhari 727
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · One woman can form a row
Narrated Anas bin Malik:
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ ، قَالَ حَدَّثَنَا سُفْيَانُ ، عَنْ إِسْحَاقَ ، عَنْ أَنَسِ بْنِ مَالِكٍ ، قَالَ صَلَّيْتُ أَنَا وَيَتِيمٌ، فِي بَيْتِنَا خَلْفَ النَّبِيِّ صلى الله عليه وسلم وَأُمِّي أُمُّ سُلَيْمٍ خَلْفَنَا.
One night an orphan and I offered the prayers behind the Prophet (ﷺ) in my house and my mother (Um Sulaim) was standing behind us (by herself forming a row).