In "Lamb to the Slaughter" what is the characterization of the woman, both direct and indirect?
Direct characterization consists on detailing the physical traits of a character in order to describe them as clearly as possible to the reader. It is the depiction of the character at face value.
Mary Malone, the young wife of a police officer, is currently pregnant. As part of her direct characterization, Roald Dahl conveys that Mary had a "slow smiling air about her", which means that Mary's face looked quite content overall. She is also directly characterized when the story reads,
Her skin [...] had acquired a wonderful translucent quality, the mouth was soft, and the eyes, with their new placid look, seemed larger darker than before.
All of these traits denote a woman that, as her indirect characterization will later show, is living at the height of her comfort zone; a niche in which she is happy and feels safe.
Indirect characterization is the extrapolation of traits as they can be inferred from circumstances. The way in which the character interacts with the environment and with other characters leads the reader to infer what are the inner traits that are not directly explained.
In Mary's case, the reader can infer from the way in which she tends to her husband so subserviently that she is what appears to be a submissive wife who believes in supporting and obeying her husband. She is obviously in love, and happy to be in the state that she is (pregnant). In Mary's mind, her husband is the center of her universe.
She loved to luxuriate in the presence of this man, and to feel-almost as a sunbather feels the sun-that warm male glow that came out of him to her when they were alone together.
However, after the incident occurs where she is told in the most nonchalant way that her husband is leaving her just like that, Mary loses it, snaps, and kills her husband by hitting his head with a frozen leg of lamb.
A lot of conclusions as far as Mary's character can be drawn, not only from this act alone, but from the fact that she went out of her way to quickly conceal any evidence. Even more so, Mary also mocks the fact that she got away with it by feeding that same murder weapon to the other police officers who went to her house to investigate the scene of the crime. The fact that she is giggling on the other side of the wall while the men ate the one piece of evidence that could have taken her straight to jail, tells that Mary could very well have gone through a psychotic episode in which she lost contact with reality and, scared about completely losing her life, she adhered to anything within her reach to save herself and her child.
What this means is that Mary is far from being merely a quiet and submissive wife: she is also a quick-thinking, witty, smart, and wiser than perhaps what her own husband would have cared to admit. Moreover, we can infer from that alone that perhaps Mary's complaisance with being a wife and mother may have been her only choice. The historical context of the story places the Malone in the early 1950's. This is a time period where the husband and wife roles were defined much differently than in modern times: this means that a natural tendency for Mary would have been to give up her own wants and interests and invest them into the marriage; she may have very well changed, from being smart and witty, to submissive and shy.
All of these are ways to characterize Mary Malone to the point where the reader can see who she is both physically and psychologically.