How does Laura respond to Buddy's infidelity and theft in the novel, Tambourines to Glory?

After seeing Buddy kissing Marietta, and then having Buddy steal a hundred dollars from her purse, Laura confronts Buddy in the basement of the church. During the confrontation, Buddy cruelly reminds Laura of the difference in their ages and admits that he stays with her only because of her money. When he pulls her in for a kiss, Laura stabs him to death with Essie's knife.