http://www.unmarriedamerica.org/News-About-Us/Anti-cohabitation.htm
Florida Statutes - Chapter 798
798.01 Living in open adultery.--Whoever lives in an open state of adultery shall be guilty of a misdemeanor of the second degree, punishable as provided in s. 775.082 or s. 775.083. Where either of the parties living in an open state of adultery is married, both parties so living shall be deemed to be guilty of the offense provided for in this section.
Good find on the adultery statute. Unfortunately, it's more complicated than this.
Florida is a "no-fault" divorce state. You only have to state the marriage is "irretrievably broken".
However, who would file the divorce papers for her? Her legal guardian. But he is the guardian. Yet another conflict of interest.
And how can he file for dissolution of marriage if she is under his charge. It's checkmate, as long as he remains the guardian.