you're looking at this backwards: you don't get some mythological list of third-year-student-research-topics and see which of them looks interesting to you and decide whether it's worth your effort do to it. you think about what interests you, and figure out a research topic from that.
so... what are you interested in? part of this assignment is to get you to think about what you want to do in nursing, and then think about how you will look at it. yep, third year is harder than second.