‘Josephine Elder’ was the pseudonym of Dr Olive Potter.  She was born in Croydon in 1895 and educated at Croydon High School, where an inspirational Botany mistress helped her to win her scholarship to Girton.  She completed her medical training at the London Hospital in Whitechapel, one of the first four women there.  After a couple of years in hospital doctor posts, she set up as a GP in Surrey.  Patients were slow to come to women doctors in the 1920s, so she turned to writing.  Her first book, Erica Wins Through (1924) was followed by nine more school stories for girls, and six adult novels (two, Sister Anne Resigns and The Mystery of the Purple Bentley)  under the further pen-name 'Margaret Potter'), including Lady of Letters (1949), The Encircled Heart (1951) and Doctor’s Children (1954).  She didn't retire until she was eighty-eight, and died five years later, in 1988.