Yes, your wife can be sued for non-payment of unsecured debt. Try consulting with a NON-PROFIT debt settlement/consolidation company, or request a free consultation with a bankruptcy attorney in your area.
*My response to your question posed on avvo.com did not create an attorney-client relationship.
The short answer is yes, she can indeed be sued. Other consequences can include the creditor writing off the debt and sending you a tax form reporting the forgiveness of debt as "income" to you for which you then have to pay taxes.
Working with a not-for-profit credit counselor may help. Depending on the amount of the debt you may also want to consult with a banruptcy attorney.
Nothing in this response as posted on www.avvo.com may be deemed to create an attorney client relationship.