Hi, and welcome to the forums!

Your wife may want to check the EU website on working in Europe here: EUROPA - EURES - the European Job Mobility Portal

There used to be some extensive information there about transfer of medical qualifications, though they have reworked the site recently, so I can't give you a quick reference. I do know that nursing and other medical qualifications can be difficult to transfer, especially if you're coming from outside the EU. But it may be possible to locate the government agency that licenses or certifies nurses, and they will surely be able to give you more information.
Cheers,
Bev