Yahya bin Ma'in يحيى بن معين · The Book of Purification

"O Messenger of Allah, Allah is not shy to tell the truth. Does a women have to perform Ghusl if she has a wet dream?" He said: "Yes, if she sees water." Umm Salamah laughed and said: "Do women really have wet dreams?" The Messenger of Allah (ﷺ) said: "How else would her child resemble her?" That is, if she has an emission of the fluid of an orgasm.

'Where were you, O Abu Hurairah?' He said: 'O Messenger of Allah, you met us but I was Junub, and I did not want to sit in your presence until I had performed Ghusl.' He said: 'Subhan Allah! The believer is not made impure (Najis).'"