Boy, I love this question. I get it 2 or 3 times a year.
In a divorce, a husband cannot force his wife to change her name! Her married name is her legal name and it is her decision if she wants to keep it or go back to any other name she has ever used.
I had one lady that liked her first husband's last name so when she divorced husband #2 she went back to husband #1's last name!
She was not doing it to avoid creditors or criminal prosecution so it was ok.