Does that count as a femme fatale? I might be wrong, but I had thought of her character less the downfall of the protagonist and more simply being rescued by him. If she weren't the edgy hooker, I would have placed her closer to the Damsel in Distress cliche.
I was kinda asking myself a similiar question tbh when that was listed. While I wouldn't call her a damsel in distress, she is surrounded by death. Sue, Pierce, Buzz - literally the first 3 characters who are with her in the car shortly after she first meets Bud White in the Bottleshop, and even White's partner Stensland, are all not long for this earth.
Even though there is no direct link to her and these deaths, she is aware of her role, which sometimes requires having to play one against the other, for whatever reason. Beside the illusion of glamour, Lynn Bracken is part of a underworld, where even though ahe is smart enough to not take the poison pill of temptation, literally Fluer-de-Lis' 'whatever you desire', she has no doubt seen what happens to so many that do, it is all around her, and she exists aware and knowingly.
Bracken is still very much a dangerous woman to know by virtue of the world she lives in, those around her and having survived in that world for some time, even before the events in the movie, that these would not be the first unfortunates who have had dealings with Lynn who would have found themselves compromized, addicted, beaten or even ended up on a slab in the morgue.
So, while I wouldn;t characterize her as a damsel in distress and perhaps not the strictest sense a Femme Fatale either, but a dangerous woman to be involved with, none the less, \nd while perhaps not the downfall of the protagonist, no doubt has lead to many downfalls beforehand and you do see glimpses of these throughout the movie, with Bracken playing a pivotal part. So I can see both sides of the arguement, that she is a femme fatale, and I suppose not, at the same time.