I don't see why there would be a problem wearing a nice skirt and blouse. I think as long as you're dressed in appropriate interview attire, you'll be fine. I was recently hired at a hospital and during that interview they asked me questions like "Tell me a time when....". For example, one question was "Tell me a time when you went out of your way to help a patient that wasn't assigned to you." I was never asked any clinical type questions. The hiring manager even started out the interview stating that they would not be asking any of those types of questions. Good luck to you!