Critics raised questions as to whether Markham was the true, or sole author of West with the Night, when her ex-husband made claims to the book. Evidence abounds that she was indeed the sole author; copies of the manuscripts sent to her editor prior to Markham meeting her ex-husband quickly silenced the critics and his claims.

Author Mary S. Lovell visited Markham in Nairobi and interviewed her extensively shortly before Markham's death, in preparation for her biography, Straight on Till Morning (1987). From her research, Lovell concluded that Markham was the sole author, although Schumacher made some basic edits to the manuscript. Instead, Lovell suggests Antoine de Saint Exupéry, another of Markham's lovers, may have served as inspiration for Markham's clear, elegant language and storytelling style.