Depends upon the individual nurse. Some are better done with Emergency Services and others are better handled by Doctor; a few are better represented by the Military occupation, relying upon their class skills to be skilled physicians.
If it's a PC then any starting occupation is acceptable, just as long as they manage to have Treat Injury as a class skill and four to eight ranks in it. They don't need the surgery feat, as many nurses are never formally trained in surgery, but there is no reason they couldn't take it as many nurses learn to become basic surgeons through a combination of observation and necessity.
Either go with the option that's best for the character's origin or pick one as the basic 'nurse' template and design the ordinaries from there.