Is the distress a fiancée feels after performing Istikhara due to magic, or is it Istikhara itself that is causing her discomfort with the marriage?

The engagement is merely a promise of marriage, and the fiancée is a stranger to the fiancé. It is not permissible for him to be alone with her or to converse with her for mere enjoyment. His conversation with her is restricted to necessity and legitimate interest. Istikhara is entrusting the matter to God. The one performing Istikhara proceeds with the matter; if it is good, God will facilitate it, and if it is evil, He will avert it. The preponderant view is to proceed with the matter even if one does not feel at ease. The fiancée's distress may have causes, or it could be due to magic, and its cure is by relying on God and diligently performing remembrances (dhikr) and legitimate ruqyah. Sins may also be a cause for this, and their cure is sincere repentance.