After World War I the Quennells wrote a series of illustrated children’s books, ''A History of Everyday Things in England'', 4 volumes (1918–1934). The series ended with ''The Good New Days'' (1935), where modern industrial and agricultural processes, together with the problems of the future, were considered. A second series was written, ''Everyday Life in…'' (1921–26) describing living from Prehistoric to Norman times. A third series of ''Everyday Things'' (1929–32) covered Greece in antiquity. After World War II she illustrated two more books in the ''Everyday Life'' series on Biblical times, the texts being written by others. She was a painter in oils and watercolour, mostly of architectural subjects.
After her husband died in 1935 she was appointed curator of the Geffrye Museum. While there she installed the series of "period rooms" on which the museum is still based to this day. She remained there until she retired in 1940, then moved to the United States
