Ben Lane' Motivation

Why did Audie Murphy's character sympathize with the femme fatale, when she had so little regard for him or for his fate. First she hires two men to bushwhack him, a total stranger who never did her any harm, solely because he is riding with Frank Jesse. Then she suicidally lights a smoky fire, evidently willing to throw his life away as well as her own to get the Apaches to kill Jesse. At the mission, she is ready to commit murder and probably doom Lane and herself.
True Frank Jesse killed her husband in a contract killing even if it was a fair fight. Why no interest in the men who hired him. Frank Jesse was just the hired gun who did what they paid him to do, it wasn't personal with him. It was personal with the two who hired him.
Frankly, I would not have turned my back on the witch.
Still I liked the picture, one I cannot recall seeing at the time or since. Duryea steals the picture effortlessly.