Here "bound by law to the husband" is a metaphor for a woman being united to her husband according to the law of marriage. AT: "according to the law, the married woman is united to the husband" (See: [[rc://en/ta/man/translate/figs-metaphor]])
You can translate this in an active form. AT: "God will consider her an adulteress" or "people will call her an adulteress" (See: [[rc://en/ta/man/translate/figs-activepassive]])
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. AT: "she does not have to obey that law"