Short answer
Ghusl is fard only if her sexual fluid (maniy) comes out with pleasure and is seen at the outer private area. A climax with no fluid seen needs no ghusl. If she only notices the slippery wetness of arousal (madhy), ghusl is not required, but wudu is broken. Masturbation itself is not permitted in the Hanafi school.
Ghusl becomes fard when a woman's maniy comes out with desire and reaches the outer part of the private area, whether in sleep, through intimacy or by her own hand. Pleasure or climax without any fluid seen does not require ghusl. Madhy (arousal fluid) and normal discharge only break wudu. Masturbation is sinful in the Hanafi school, apart from a narrow concession for one who fears falling into zina.
The four schools agree on this.
Explanation
This question has two parts: the purity ruling and the ruling on the act. For purity the rule for women is the same as for men. When Umm Sulaym asked whether a woman must bathe after a wet dream, the Prophet ﷺ said yes, if she sees the fluid. He also described a woman's fluid as thin and yellowish, and a man's as thick and white.
Three fluids, three rulings:
- Maniy: released at sexual climax, usually with a sense of release and then relaxation. Ghusl is fard.
- Madhy: the clear, slippery wetness of arousal, without climax. Wash the area and make wudu; no ghusl.
- Ordinary discharge: breaks wudu only. See does discharge break wudu.
Women often find it harder than men to tell maniy from madhy. The deciding factor in the Hanafi school is whether fluid is seen. If you climaxed and then find wetness at the outer private area, treat it as maniy and take ghusl, since madhy comes with arousal, not with climax. If you climaxed but no fluid came out at all, there is no ghusl. If there was arousal without climax and only slippery wetness, wash and make wudu. The same applies to a wet dream: ghusl only if you wake to find the fluid. See ghusl after a wet dream.
The act itself. The Hanafi school does not allow masturbation as a habit or for pleasure, and the Shafi'i and Maliki schools forbid it in all cases. The details, and a way out if you are struggling, are in is masturbation haram. Do not let shame stop you from praying: take ghusl, repent and carry on. Allah loves those who keep turning back to Him.
The evidence
Quran, Surah Al-Maaida 5:6
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ إِذَا قُمْتُمْ إِلَى ٱلصَّلَوٰةِ فَٱغْسِلُوا۟ وُجُوهَكُمْ وَأَيْدِيَكُمْ إِلَى ٱلْمَرَافِقِ وَٱمْسَحُوا۟ بِرُءُوسِكُمْ وَأَرْجُلَكُمْ إِلَى ٱلْكَعْبَيْنِ ۚ وَإِن كُنتُمْ جُنُبًۭا فَٱطَّهَّرُوا۟ ۚ وَإِن كُنتُم مَّرْضَىٰٓ أَوْ عَلَىٰ سَفَرٍ أَوْ جَآءَ أَحَدٌۭ مِّنكُم مِّنَ ٱلْغَآئِطِ أَوْ لَٰمَسْتُمُ ٱلنِّسَآءَ فَلَمْ تَجِدُوا۟ مَآءًۭ فَتَيَمَّمُوا۟ صَعِيدًۭا طَيِّبًۭا فَٱمْسَحُوا۟ بِوُجُوهِكُمْ وَأَيْدِيكُم مِّنْهُ ۚ مَا يُرِيدُ ٱللَّهُ لِيَجْعَلَ عَلَيْكُم مِّنْ حَرَجٍۢ وَلَٰكِن يُرِيدُ لِيُطَهِّرَكُمْ وَلِيُتِمَّ نِعْمَتَهُۥ عَلَيْكُمْ لَعَلَّكُمْ تَشْكُرُونَ ﴿٦﴾
O you who have believed, when you rise to [perform] prayer, wash your faces and your forearms to the elbows and wipe over your heads and wash your feet to the ankles. And if you are in a state of janabah, then purify yourselves. But if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and do not find water, then seek clean earth and wipe over your faces and hands with it. Allah does not intend to make difficulty for you, but He intends to purify you and complete His favor upon you that you may be grateful.
Ghusl is required from major impurity.
Quran, Surah Al-Baqara 2:222
وَيَسْـَٔلُونَكَ عَنِ ٱلْمَحِيضِ ۖ قُلْ هُوَ أَذًۭى فَٱعْتَزِلُوا۟ ٱلنِّسَآءَ فِى ٱلْمَحِيضِ ۖ وَلَا تَقْرَبُوهُنَّ حَتَّىٰ يَطْهُرْنَ ۖ فَإِذَا تَطَهَّرْنَ فَأْتُوهُنَّ مِنْ حَيْثُ أَمَرَكُمُ ٱللَّهُ ۚ إِنَّ ٱللَّهَ يُحِبُّ ٱلتَّوَّٰبِينَ وَيُحِبُّ ٱلْمُتَطَهِّرِينَ ﴿٢٢٢﴾
And they ask you about menstruation. Say, "It is harm, so keep away from wives during menstruation. And do not approach them until they are pure. And when they have purified themselves, then come to them from where Allah has ordained for you. Indeed, Allah loves those who are constantly repentant and loves those who purify themselves."
Allah loves those who keep returning to Him in repentance.
Sahih al-Bukhari 130
Sahih... إذا رأت الماء ...
"If she sees the fluid."
A woman's ghusl after a sexual release depends on the fluid being seen.
Sahih Muslim 311
Sahih... ماء الرجل غليظ أبيض وماء المرأة رقيق أصفر ...
"A man's fluid is thick and white, and a woman's fluid is thin and yellow."
Describes a woman's maniy, which helps tell it from other wetness.
Where the ruling is recorded
- Nur al-Idah with Maraqi al-Falah, Kitab al-Taharah, chapter on what makes ghusl obligatory. Ghusl is due when maniy separates with desire and comes out.
- al-Durr al-Mukhtar, Kitab al-Taharah, the things that make ghusl fard. Madhy and wadi require only wudu.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.