Erle Stanley —, author of 1937 novel The D. A. Calls It Murder and others featuring Doug Selby (7)
I believe the answer is:
gardner
(Other definitions for gardner that I've seen before include "Ava ..., glamorous old film star" , "Writer of detective books" , "US actress. wife of Mickey Rooney, Artie Shaw and Frank Sinatra, d. London, 1990" , "Erle Stanley ..., Ava ..." , "Ava --, US actress" .)