Thank you for your question.
This following recommendation is not legal advice. It comes from someone familiar with how pedophiles "groom" their victims, and findings of decades of research into the brain works and social dysfunctions of mammals.
Call Ohio's version of Child Protective Services/Department of Family and Child Services, and report sexual harassment by the new husband. Calmly and without getting into the "and oh by the way he's ugly too" nonsense.
The new "husbands" of fertile female mice and rats will literally eat the young of the prior "husband", so to speak. Human male rats don't cannibalize their step-children, but they are far, far more likely to take sexual liberties with step-children than they do with their own flesh and blood.
If "coaching" a new potential victim to be comfortable with the offender doesn't work, then ridicule and threat of public humiliation and pointing out that "mommy" will never believe the child if the victim truly reports even attempted sexual abuse is the next step. Sexual predators inside "family" settings rarely need to resort to force or threats of force.
A consultation with a local family law attorney familiar with how YOUR courts
handle these situations would be wise. Even with the "good faith reporting" privilege that a person has under the law, there are often some useful "dos" and "don't dos" to consider before creating the trail of evidence of what you know and when and how you report it.
Thank you and good luck with this. I'll eat my words if the new husband is not a pervert of some sort--non-pedophiles often justify their, ummm, preferences with inappropriate behavior, just so they can contrast themselves with the more dangerous predators.