Red Country by Joe Abercrombie

They burned her home.

They stole her brother and sister.

But vengeance is following.

Shy South hoped to bury her bloody past and ride away smiling, but she'll have to sharpen up some bad old ways to get her family back, and she's not a woman to flinch from what needs doing. She sets off in pursuit with only a pair of oxen and her cowardly old stepfather Lamb for company. But it turns out Lamb's buried a bloody past of his own, and out in the lawless Far Country, the past never stays buried.

Book by author Joe Abercrombie.