Guide female doctor around emergency room (8)

I believe the answer is:
shepherd
'guide' is the definition.
(I've seen this before)
'female doctor around emergency room' is the wordplay.
I cannot quite understand how this works, but
'female' could be 'she' ('she' refers to a woman) and 'she' is present in the answer.
'doctor' could be 'd' (eg in PhD, Doctor of Philosophy) and 'd' is found in the answer.
'emergency room' could be 'er' (abbreviation popularized by US TV series) and 'er' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for shepherd that I've seen before include "A minder of lambs and rams" , "Flock watcher" , "Pastor" , "Animal tender" , "Saturn's moon" .)