I say, and with God's success: It is required under the condition of emission, and there is no difference between a man and a woman in this; for Umm Salama, may Allah be pleased with her, said: "Umm Sulaim came to the Prophet, peace be upon him, and said: O Messenger of Allah, Allah does not shy away from the truth, is there a requirement for a woman to perform a ghusl (ritual bath) if she has an emission?" The Messenger of Allah, peace be upon him, said: "Yes, if she sees the water," in Sahih Muslim 1: 251, and Sahih Bukhari 1: 108. And Aisha, may Allah be pleased with her, said: "The Messenger of Allah, peace be upon him, was asked about a man who finds moisture but does not remember having an emission, he said: he should perform ghusl, and about a man who thinks he has had an emission but does not find moisture, he said: there is no ghusl upon him. Umm Salama said: O Messenger of Allah, is there a ghusl upon a woman who sees that? He said: Yes, women are the counterparts of men," in Sunan al-Tirmidhi 1: 190, and the smaller Sunnah 1: 112, and Al-Muntaka 1: 33, and Sunan Abu Dawood 1: 78, and Musnad Ahmad 6: 256. See: Tabyin al-Haqaiq 1: 16, and Allah knows best.