On the title page of her children's story, Wanted - A Servant, Gertrude Hart is listed as joint author of The Man Next Door , which is by T. L. O. A. The other joint author is believed to be Gertrude's sister, Annie, who collaborated in her writing.
The initials presumably stand for 'Two Ladies of Australia'. Compare the pseudonym of the popular writer for girls, Charlotte Maria Tucker (1821-1893), 'A. L. O. E.' ('A Lady of England').