Iron Widow (American Post-Civil War Westerns) by William Black

Widowed railroad heiress Beth Huntington must adapt or die. With cutthroat rivals and hired guns hunting her fortune, she flees to the lawless west with her son. There, Sheriff Harlan Reeves teaches her the frontier’s brutal code: ‘Become the wolf – or be eaten.’ But as enemies close in, can a refined woman learn savagery fast enough to survive?