Sunan An-Nasai, Chapter: The Book of Purification

"Naim the freed slave of Umm Salamah narrated to me that Umm Salamah was asked: 'Can a woman perform Ghusl with a man?' She said: 'Yes, if she is well-mannered.* I remember the Messenger of Allah (saw) and I performing Ghusl from a single wash tub. We would pour water on our hands until they were clean then pour water over them.'" Al-Araj said: "Not mentioning the private area nor paying attention to it." (Sahih) *Kaisyah: "Well-mannered when using the water with the man." (An-Nihayah) And the comments by Al-Araj after the narration refer to its meaning.