Musannaf Ibn Abi Shayba 1:878

Abu Bakr narrated to us, he said: Waki' narrated to us, from Hisham ibn 'Urwah, from his father, from Zaynab bint Umm Salamah, from Umm Salamah, who said: Umm Sulaym came to the Prophet, may Allah bless him and grant him peace, and asked him about a woman who sees in her sleep what a man sees. He said: "If she sees the fluid, then she must perform ghusl." I said to her: "You have disgraced the women! Does a woman have wet dreams?" The Prophet, may Allah bless him and grant him peace, said: "May your right hand be covered in dust! For what does her child resemble her if [not that]?"