In "Lamb to the Slaughter," how does Mary Maloney's worry show itself at the beginning of the story?
When Mary Maloney's husband gets home from work, there are signs of stress; he drinks all of his drink in one gulp, is non-communicative, and seems especially tired. Mary is concerned; she worries about him and the day that he has had. She wonders what has made him so tired. Mary's worry manifests itself through fretting, additional offers of service, extra attention and care, and probing questions.
For example, as he downs his drink, she jumps up and offers to get him another. When he has another one, she offers to get his slippers, and she peppers him with commentary, meant to show that she cares; she laments that work keeps him on his feet all day. She asks if he wants some cheese before they go out; she says they don't even have to go out if he doesn't want to. Her worry shows in increasing inquiries and talking; it fills up the empty silence, and to her, shows him that she cares. He doesn't respond to any of this, and then she becomes restless and gets up to make dinner.
Mary's anxiety shows itself through an increase in conversation on her part--she's a nervous talker. She insists on serving him more, even though he declines. She is desperately just trying to talk the awkwardness away, or to ease the discomfort through action. In the end, it is she that is going to get the "shock" of her life; after that, she behaves without any nervousness at all, taking what happened in stride. I hope that those thoughts helped; good luck!