I read 'A Murderous Muse' and was curious about the same thing. My take is, not directly. The book's central murder case is wholly fictional, which the author's note clarifies. But the novel weaves in so many real, grim details about Victorian London's art scene and forensic science that it ‘feels’ true. You get that heavy, factual atmosphere of places like the Royal Academy and the early procedures of Scotland Yard.
The narrative leans into real social tensions of the era—the anxiety over new photography techniques threatening painting, the squalor of the rookeries. It uses these truths as a scaffold for its own invented darkness. So, while the muse herself and her victims are creations, the world that created her absolutely existed. That blurring is what gave me chills, honestly.
Finishing it left me down a rabbit hole reading about pre-Jack the Ripper London crime reports, which I think was the point.