Is it permissible for a woman suffering from severe fear and a change in her eyes to perform ghusl with water that was used to wash a deceased person?

Using water that is not known to be a means of healing, neither Islamically nor empirically, is considered minor shirk (polytheism), because it attributes cause to something that is not a cause. The woman should perform ruqyah (Islamic incantation) on herself with the prescribed incantations, such as Al-Fatihah and Al-Mu'awwidhatayn, and she can also consult doctors.