Final answer:
In Dahl's 'Lamb to the Slaughter,' the wife defies traditional gender roles by proactively altering her fate in response to her husband's actions, symbolizing a shift from traditional subservience to assertive independence.
Step-by-step explanation:
The wife in Dahl's "Lamb to the Slaughter" breaks traditional gender roles in a marriage primarily by taking charge of her own destiny after she experiences a grievous betrayal. This act contrasts sharply with traditional expectations of women as being submissive and adhering to a primarily domestic role. Through this narrative, the story challenges the social norms of the time and reflects the broader struggle for women between traditional and modern societal and cultural standards, a struggle that continues to be relevant in various forms throughout history.