I posted earlier without researching. Accordingly, I have deleted the incorrect response I gave.
Rmet is correct re Michigan law. Ohio, however, has no specific prohibition against marriage between persons formerly related by marriage.
RMET: None of the states I am familiar with have laws against marriage between persons who are not related within a certain degree of consanguinuity. Further, I am accustomed to the concept that the dissolution of the marriage also terminates the stepparent-stepchild relationship as well. How common have you found such prohibitions to be?
I was hitchhiking the other day and a hearse stopped. I said, "No thanks--I'm not going that far." --Steven Wright