Can you imagine how utterly embarrassed that nurse must feel today? She probably hung up from that call in total shock - and perhaps pride - that she had just spoken to "the Queen" and "the Prince of Wales". I can almost picture her turning to whichever co-worker was nearby and relaying her conversation with the "royals". Nobody in her life will likely ever let her live this down.
Of course, what she did was flatly wrong, and frankly stupid (I read the transcripts of the call, and it seems that anyone sufficiently educated to have been chosen as private nurse to a member of the royal family would have been able to figure out they were being duped)! And no doubt their rules state that even if God himself called, you can't release medical information.
But I know several nurses and how hard and long hours they work. She could have been exhausted from a long shift, and taken off guard by having an unexpected call from "the sovereign" put through to her. Poor thing - probably assigned to change bedpans the rest of the week, and no doubt will never be allowed in a VIP ward any longer.