When Is Ghusl Compulsory for a Woman?
Question

If a female has an orgasm without intercourse, is she required to perform ghusl before she can say her prayers?
Praise be to Allah.If maniy (fluid emitted at the point of climax) comes out of a woman without intercourse, she has to do ghusl . The Prophet (peace and blessings of Allah be upon him) commanded women to do ghusl if they notice water (fluid), as was reported by Malik in al-Muwatta (1/51), and by al-Bukhari (282) and al-Nasai (1/114) from Umm Salamah (may Allah be pleased with her) who said: Umm Sulaim, the wife of Abu Talhah, came to the Messenger of Allah (peace and blessings of Allah be upon him) and said, “O Messenger of Allah, Allah is not too shy to tell the truth. Does a woman have to do ghusl if she has an (erotic) dream?” He said, “Yes, if she sees water (fluid).” In this hadith, he (peace and blessings of Allah be upon him) commanded women to do ghusl if they see water, i.e., maniy.
 Al-Baghawi said in Sharh al-Sunnah (2/9): 
“Ghusl for janabah (impurity following sexual activity) is wajib (obligatory) if either of the following applies: either the tip of the penis penetrates the vagina, or the gushing liquid is emitted by the man or the woman… The scholars said that ghusl does not become obligatory unless one is sure that what one feels of wetness comes from the gushing liquid.”
 Ibn Qudamah said in al-Mughni (1/200): 
“The Prophet (peace and blessings of Allah be upon him) connected doing ghusl to seeing (the fluid) when he said: “If you see the water and if the water gushes out , then do ghusl.” The ruling does not apply otherwise.”
 Ibn Hajar said in al-Fath (1/389): 
“This indicates that ghusl is obligatory for women, if they emit fluid at the point of climax.”
Ibn Rajab said in al-Fath (1/338): 
“This hadith indicates that if a woman sees an (erotic) dream and notices the fluid when she wakes up, she has to do ghusl. This was the view of the majority of scholars and no dissenting view is known except for that of al-Nakha’i, who is the odd one out.”
This hadith of the Prophet (peace and blessings of Allah be upon him) makes the matter quite clear, which is that if any fluid is emitted by the woman – whether it is a little or a lot – then she has to do ghusl.
On the basis of the above, if a woman feels that some fluid has come out of her vagina, even if it is only a little, then she has to do ghusl, because of the report to that effect. It is not sufficient for her to do wudu in this case unless the fluid which was emitted was not the kind of fluid for which ghusl is required, such as madhiy (lubricating secretion) etc., in which case wudu is sufficient. 
And Allah knows best.