It depends on whether you want it to show what someone would expect a nurse to look like, or show what a nurse. Nothing in the definition of a nurse implies female.
If you ask for a female US president, should the application simply return a black screen?
If you ask for a black US president, would you expect it to only ever return pictures of Barack Obama?
I agree nothing in the definition of nurse implies female, but something in our culture definitely has "nurse -> female". Likewise, nothing in "college student" definitionally implies age, but I wouldn't consider it a success if my system displayed a picture of a 9 year old.
>> Nothing in the definition of a nurse implies female.
Unfortunately it's not a great example with which to make this point. Before Florence Nightingale, a nurse was a person who was employed to suckle your babies. Of course 100% were female.
Wet nurse was a later coining to differentiate the two meanings.
If you ask for a female US president, should the application simply return a black screen?
If you ask for a black US president, would you expect it to only ever return pictures of Barack Obama?