Is this really orderly? Doesn't it mean nurse?
Yes, exactly, it means "(female) nurses".
I am an English native speaker, yet have no idea what the word "orderly" means? Is it American or Australian? Does it mean an ordinary soldier?
I suspect it is being used here in the sense of an auxiliary or nursing assistant, but while it can be used in a medical context I agree it would normally suggest the military.
I'm American and I think of a hospital orderly as a guy without medical certification who helps out, maybe delivering patients or stocking supplies. This may be a part-time job while he's training to be a nurse.