In case a woman sees that, she must take a bath. Umm Sulaim said: I was bashful on account of that and said: Does it happen? Upon this the Messenger of Allah (ﷺ) said: Yes (it does happen), otherwise how can (a child) resemble her? Man's discharge (i. e. sperm) is thick and white and the discharge of woman is thin and yellow; so the resemblance comes from the one whose genes prevail or dominate.
Sahih Muslim Book 3, Hadith 32
← Previous Hadith Umm Sulaim who was the grandmother of Ishaq came to the Messenger of Allah (ﷺ) in the presence of 'A'isha and said to him: Messenger of Allah, in case or woman sees what a man sees in dream and she experiences in dream what a man experiences (i. e. experiences orgasm)? Upon this 'A'isha remarked: O Umm Sulaim, you brought humiliation to women;may your right hand be covered with dust. He (the Holy Prophet) said to 'A'isha: Let your hand be covered with dust, and (addressing Umm Sulaim) said: Well, O Umm Sulaim, she should take a bath if she sees that (i. e. she experiences orgasm in dream).

Sahih Muslim Book 3, Hadith 31 Next Hadith → A woman asked the Messenger of Allah (way peace be upon him) about a woman who sees in her dream what a man sees in his dream (sexual dream). He (the Holy Prophet) said: If she experiences what a man experiences, she should take a bath.

Sahih Muslim Book 3, Hadith 33