You can translate this in an active form. Alternate translation: "God will consider her an adulteress" or "people will call her an adulteress" (See: [[rc://en/ta/man/translate/figs-activepassive]])
Here being free from the law means not having to obey the law. In this case, the woman does not have to obey the law that says that a married woman cannot marry another man. Alternate translation: "she does not have to obey that law"