A potentially tragic interpretation of this is that Zoey's mom understands that she's being abused by her husband, but endures it to keep his rage from transferring to her children. She's no longer a single mom with three young children; her family lives in a nice house in the suburbs with financial security. In the meantime, she receives the brunt of his control and abuse. She changes her reading habits, her religion, her behavior, and her style. She allows him to dictate who she sees and who her friends are. The more she submits, the less he harasses her children.

When Zoey comes home marked, Mom knows it's game over. There's no way her husband will ignore this like he usually ignores things, and she freaks out. She can't keep her daughter safe from vampires and she can't keep her safe from her husband. A crackdown on Zoey would mean a crackdown on the other children, too. Everything that she tried so hard to preserve is about to come crashing down.

And then Zoey throws that diatribe in her face.