Hi, I'm Scott,
First, I need to disclose that I am licensed in California, not Iowa, and in any case, lawyers here cannot provide specific legal advice because no lawyer-client relation exists. Consequently we can only speak to legal generalities, but that can help people get some perspective.
First, you personally cannot make criminal "charges" -- you can file a criminal complaint, but it is up to local law enforcement whether to follow through with a particular prosecution.
Given the scenario described, your remedies will lay in your defense and otherwise in potential civil actions.
In this day and age, allegations of domestic abuse tend to have authorities erring on the side of hypercaution and in favor of the person making the allegations.
When it comes time to defending against such allegations in a court of law, the prosecution will have to "prove beyond a reasonable doubt." So, if there was no physical abuse, and the person making the allegations have no corroborating ]witnesses or medical evidence to substantiate it, it comes down to he said/she said, and who is more believeable. In such cases, it's imperative the legal representative has enough information and witnesses to discredit the person who made the allegations of abuse: history of the lies and fraud and any and all other incidents of dishonesty.
Former husbands who have been lied to and treated similarly are ripe, and that may establish a pattern if she made similar allegations in the past.
With respect to the other facets, you really should consult with an attorney licensed in your jurisdiction for both the criminal and civil actions.
You should not feel self-conscious about seeking a second legal opinion, and I urge you to do so.
I understand it's another consultation fee, but it may prove invaluable in terms of yourr reputation, criminal record and long term financia/creditl health: please don't let these facets go unattended!