Steele wrote in The Living Year, "I did not become a writer, but was born one, waking up in the morning to sort the day into scenes and characters and descriptions."
One of her few books for adults, The Living Year: An Almanac for My Survivors (Viking, 1972) features Tennessee natural history.
The Secret of the Fiery Gorge (1960) was her "first work of some interest in the field of the fantastic", according to John Clute.
Its protagonists "live Underground in Pocket Universe environment" (capitals indicate encyclopedia cross-references).
[2] WorldCat libraries report Mathilde and Matilde titles by Mary Q. Steele, in French and Spanish translation.