Sunan Ibn Majah
Hadith #601
It was narrated from Anas that:Umm Sulaim asked the Messenger of Allah about a woman who sees in her dream something like that which a man sees. The Messenger of Allah said: ""If she sees that and has a discharge, then let her perform a bath."" Umm Salamah said: ""O Messenger of Allah, does that really happen?"" He said: ""Yes, the water of the man is thick and white and the water of a woman is thin and yellow. Whichever of them comes first or predominates, the child will resemble (that parent)