This hadith was narrated by Zainab from her mother and from Zainab, the wife of Allah's Apostle (ﷺ), or from some other lady from among the wives of the Prophet (ﷺ).
وَحَدَّثَتْهُ زَيْنَبُ، عَنْ أُمِّهَا، وَعَنْ زَيْنَبَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم أَوْ عَنِ امْرَأَةٍ مِنْ بَعْضِ أَزْوَاجِ النَّبِيِّ صلى الله عليه وسلم .
Muslim
The Book of Divorce • Hadith 75