I met a baby Mabel the other day. I just about managed to contain my laughter.
What has happened here is that certain old-lady names (Rose, Lily &c) have become fashionable, and some people have tried to be one step ahead by choosing granny names that haven't yet become popular. The trouble is that these names are unpopular for a reason - they are hideous. Daphne and Nancy have an old-fashioned glamour to them. Ethel is just an old bag's name.