Legal Question in Family Law in Michigan

You can't sue them for the information or force them to tell you, if that's what you mean. However, you can do your own internet research or hire someone to assist you, if you have any information about her. How many times have you asked them and/or discussed this with them? Perhaps there is a reason they don't want you to know her. What it could be, i'm not sure. However, if you approach the subject maturely, and perhaps several times, maybe they will come around and give you the information you need to find her.