It is important to start with the function of Mrs. Peters as a character and how she, and her gradual change, are used in the play. Mrs. Peters is used to exemplify the kind of gender relations and power inequalities within those relations that mark out this play. Her gradual development indicates one of the most powerful themes of the play - that women will become overtly aware of their powerless situation and act to do something about it.
Mrs. Peters is the wife of the Sheriff and at the beginning of the play is a meek, submissive and subservient character. The introductory stage directions describe her as a "slight, wiry woman, with a thin, nervous face". She also expresses the preoccupations of women by her reference to the fruit freezing and how Mrs. Wright was concerned about her jars. This triggers of the most memorable line of the play, delivered by Hale: "Well, women are used to worrying over trifles." Mrs. Peters also defends the work of the men when Mrs. Hale criticises their attitude, showing her subservient position.
Throughout the course of the play though, Mrs. Peters is persuaded by Mrs. Hale to recognise the gender inequalities that existed not only between the Wrights (through the discovery of the motive) but also within her own marriage. Despite her protestation that "The law has got to punish crime", she is described as "pulling herself back", showing that she is shaking in her resolve and is moving towards agreeing with Mrs. Hale. What interestingly seems to push Mrs. Peters into acting is the Attorney's assertion that she didn't need supervising because she is "married to the law" - this patriarchal assumption that Mrs. Peters, as a female, is unable to think for herself and act on her own initiative and is merely subservient to her husband echoes the position of women as shown in the marriage of the Wrights. Although her act of trying to hide the "motive" for the murder fails, it indicates her first step towards challenging patriarchy and shows her awakening as to her true state.