Katherine Vinder is the daughter of Karl Vinder, the owner of Sandpoints general store and trading post. She is generally standoffish to other women, as she has a reputation for being too easy to catch. The truth is that Katherine has only been with two men, and her reputation came from one of those men spreading terrible lies about her. She has confided to Lyssa that Benjamin Avery, the mill worker who she sees regularly, is in fact cruel and abusive. She claims that during the time they have been together he has taken delight in having his friends spread stories of her "unnatural lusts", threatening to hurt her younger sister, Shayliss, if she tries to tell anyone the truth. Katherine does have a tendency to embellish the truth in her own favor, so this accusation might or might not be accurate, but she certainly seemed to believe when she swore Lyssa to secrecy.
She has also confided in Lyssa that the other man she has been with might be able to help her in some way. She has refused more details, but seems hopeful that the gentler of her lovers might be able to save her from Ben's cruelty.