Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) was asked about a woman who sees in her dream what a man sees, and the woman has a wet dream. The Prophet (peace and blessings be upon him) said: "If she has a discharge just as a man has a discharge, then a ritual bath (ghusl) is obligatory upon her; and if she does not have a discharge, then nothing is required of her."
Al-Tabarani recorded it in al-Mu'jam al-Awsat, and it is recorded in the Sahih in abridged form. Its chain contains a narrator, Abdullah bin Isa al-Khazzaz, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1453