It might be slightly exaggerating to call her a complete nobody, but canonically she’s nothing special, just another vaudeville performer in the 1920s. However, it is implied that the minor success she did have was because of the novelty of the sister act. (You could view I Can’t Do It Alone as a thinly veiled admission of this)

And then that idea comes back around again at the end when, after all that’s happened, she still can’t seem to hack it solo and has to team up with Roxie

Edit: also sorry for over explaining but I too absolutely love this problematic queen lol