We are married she says its her families money and her brother received at least as much,I believe my wife wants a divorce.

One would need more facts to answer your question, so I can only answer it generally. Under Wisconsin law, when getting a divorce, all property, whether acquired before or during the marriage, it is presumed to be divided equally at the time of the divorce. The only property that is exempt is property acquired by gift or inheritance from a third party. If your wife can show that she acquired this money from her family by way of gift or inheritance, and kept it separate and distinct from the marital estate, it would be exempt from property division. The only exception would be if she commingled the separate asset into the marital estate or if you can show it would create a hardship not to divide the separate asset.