Believe me, I feel for your wife as after doing a past grad degree by distance education I had writers block on many occasions and it is a really frustrating, lonely and upsetting experience. All I can offer is advice to your wife from my own experience.
First, contact your course coordinator immediately and discuss with him or her the problems you are having and see if they can offer any suggestions. At the very least, get an extension on your essay! Be really upfront about your trouble, they will often give you pointers. Access library resources too, using the help of a skilled librarian; often the internet is just too big too negotiate when you are researching this type of topic.
I would also suggest that you research the topic of Androgogical learning; this is a theory of adult learning that gives guidelines on how adult education should be pursued (as opposed to traditional pedagogical methods).
Until recently, I was a clinical nurse educator, and recent developments in the field suggest that presentation of Critical Incidents (a popular concept in nursing theory today, so shouldn't be too hard to research it) followed by discussion in small groups is the best way to go. Evaluation with this procedure varies, but is generally more qualitative than quantitative, and usually takes the form of short pre and post session written questionnaires inviting open-ended comments on the educational session, and perhaps a simple rating scale (eg how useful was this, how clear was the presentation etc).
It is also quite difficult to attract nurses to educational sessions! I found getting feedback on waht they wanted to hear, as well as what time was convenient for them, was useful in improving satisfaction as well as making the presentation interesting and relevent to real life (this is where Critical Incidents really work),a certificate of attendence (looks good in the resume!) and maybe having a little socialising, refreshment etc after.
I don't know if this helps, but remember; if it just isn't happening for you, get something down on paper and hand it in, rather than giving up and pulling out altogether!