Your wife is having severe muscle spasm. This could be due to various reasons. Continuously holding neck in one particular direction can cause overuse of muscles leading to severe tightness. Any fall or trauma can cause this kind of spasm.
Next Steps
Please apply ice pack every 2 hours. Give rest to neck. Get a muscle relaxant prescribed by your family physician. Slowly do movements in pain free ranges.
Once the pain subsides then do chin tucks and shoulder retraction exercises.
Health Tips
Do not do any kind of massage on the neck.