A good way to find an article written by a nurse in the CINAHL database is to run your search and use the Journal Subset "Nursing" underneath the filter options to limit to only nursing journals. Chances are very good that an article in a nursing journal will be written by a nurse. Check the credentials of the authors to be sure. Another way is to check the boxes labeled "First Author is Nurse" or "Any Author is Nurse".

In SuperSearch, there is not as easy a way to limit. You will need to use a keyword such as nursing or RN and check credentials on individual articles.