Death of step-sons
The death of the stepsons is a metaphor for the concept of karma. They were so determined to blacklist the witch even though there was no proof she had killed her husband, but they were instead met with their own demise.
The Poison
The “poison” is a metaphor for fear towards natural remedies. Indeed, many had superstitious beliefs about concocted one’s own medicine, and on top of that, having a woman assume the role of a doctor was almost unheard of.
The Witch
The Witch is perhaps a metaphor for the oppression that women faced at the time. As an unusual, free, independent woman, she was immediately labelled as an outcast by a society that did not understand her.