Not as unknown as some others in this feature, possibly because Nick Lowe wrote a song about her.

Mary Provost did not look her best
The day the cops bust into her lonely nest
In the cheap hotel up
On Hollywood West July 29
She'd been lyin' there
For two or three weeks
The neighbors said
They never heard a squeak
For hungry eyes that could not speak
Said even little doggie's have got to eat

She was winner
The became the doggie's dinner
She never meant that much to me
(But now I see) Oh poor Mary

After a few popular movies, Warner Brothers let her go. I don't know why. Perhaps she was baffled as well. She started drinking and eating, and after a few personal reversals went full lush. Died of the bottle in 1936. As for being a doggie's dinner:

Despite Nick Lowe and Hollywood Babylon, the truth is that her poor distressed pet was only trying to rouse his sleeping mistress. The police report clearly states that the dog “had chewed up her arms and legs in a futile attempt to awaken her.”

Kenneth Anger exaggerated something? You don't say.