Thank you for all the advice. We own a condo in her home country and spend the summers there (we are both teachers). Once we retire, we plan to spend 6 months there and 6 months back in the U.S. (and thus don't want to have to get an IDP every year). She never got a European license before emigrating to the US (her first was in our home US state). I think she will be ok in taking the test and getting a European license in addition to keeping her US one. But, wish us luck!!!