Marie Windsor as Mary Carson / Doll Brown in HELLFIRE (1949). I discovered this excellent and underrated western thanks to an interesting screen capture of HELLFIRE co-star Forrest Tucker used by blogger Hal Horn on his Twitter page.

More on the film and Tucker:
HELLFIRE reviewed by Hal Horn
Hal Horn’s Salute to Forrest Tucker

Other recommended links with images (from 50 Westerns From The 50s):
Netflix Alert: HELLFIRE (1949)
Marie Windsor as Doll Brown