Since when are GPs/family doctors ever in a position to "prescribe blood" or "administer blood"?
I wonder what she does when one of her patients, or better yet an anemic patient would greatly benefit from a few pints of blood. Does she pass the patient on to another Dr. or does Sister Doctor actually prescribe blood when needed. That's something that her patients need to take into consideration if they know her JW standing.
All that's needed to find out her Dub standing is to ask her how she feels about prescribing blood for her patients and watch her facial reactions and listen to see if she doesn't give a definitive answer. If she can't answer directly and firmly it's time to find a new family physician and perhaps report her to the board if she doesn't believe in administering blood.