Sahih Muslim 312
Sahih Muslim · Book 3: The Book of Menstruation · Women are obliged to perform ghusl if they emit fluid
Anas b. Malik reported:
حَدَّثَنَا دَاوُدُ بْنُ رُشَيْدٍ ، حَدَّثَنَا صَالِحُ بْنُ عُمَرَ ، حَدَّثَنَا أَبُو مَالِكٍ الأَشْجَعِيُّ ، عَنْ أَنَسِ بْنِ مَالِكٍ ، قَالَ سَأَلَتِ امْرَأَةٌ رَسُولَ اللَّهِ صلى الله عليه وسلم عَنِ الْمَرْأَةِ تَرَى فِي مَنَامِهَا مَا يَرَى الرَّجُلُ فِي مَنَامِهِ فَقَالَ " إِذَا كَانَ مِنْهَا مَا يَكُونُ مِنَ الرَّجُلِ فَلْتَغْتَسِلْ " .
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.