It was narrated from Umm Salamah that a woman said:
"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."[1] Umm Salamah laughed and said: "Do women really have wet dreams?" The Messenger of Allah (ﷺ) said: "How else would her child resemble her?"[1] That is, if she has an emission of the fluid of an orgasm. (JA)
English reference (JA): Vol. 1, Book 1, Hadith 197 (JA)
Arabic reference (JA): Book 1, Hadith 198 (JA)