Divorce and last name?

fiance divorced in september. in the divorce she state that she wanted to change her name back to her maiden name, right before the judge granted the divorce he asked if she wanted to changer her name back to her maiden name and she had said yes. now she hasnt changed it and she just got a tattoo (n.j.s) well the s is my fiances last name her maiden name is with a c.. my question is bc she stated in both divorce paper and in the record in court is there anyway we can make her change the name. please no comments other than the yes or no answer and if yes how to do so?