[citation needed] Avery was born 30 September 1926 in Reigate, Surrey and attended Dunottar School.
[4] Avery worked first as a journalist on the Surrey Mirror, then for Chambers's Encyclopaedia and Oxford University Press.
The first, The Warden's Niece (1957), is a witty adventure story in which Maria runs away from her stultifying boarding school to live with her great-uncle, the head of an Oxford college.
Impressed by her academic ambitions (she wants to become Professor of Greek), he decides to let her stay, and she proves her abilities as a researcher by uncovering a piece of history from the English Civil War.
Characters from The Warden's Niece reappear in The Elephant War (1960), which is about an attempt by the London Zoo to prevent the sale of Jumbo to P. T. Barnum, and in The Italian Spring (1962).