Answered by Ustadha Shazia Ahmad
If a woman masturbates, does she have to perform ghusl?

As previously explained in an answer for a question on masturbation, one must remember that masturbation is haram and that it can affect one adversely in many ways. It may seem enjoyable at first, but incurring the displeasure of Allah, Most High, and disrupting one’s own sexual and mental health will prove to be detrimental.
That being said, if she does masturbate and orgasmic sexual fluid exits from her, she must perform the purificatory bath (ghusl). If sexual fluid does not exit from her, or if she has a dry orgasm where nothing at all exits, then a ghusl is not obligatory. (Reliance of the Traveller, e10.0)
And Allah knows best.
Shazia