Susan Glaspell's play Trifles features two female lead characters: Mrs. Hale and Mrs. Peters.
Mrs. Hale is a farm wife and the wife of Mr. Hale, a witness for the prosecution of Minnie Wright for killing her husband, John.
Mrs. Hale met Minnie Wright before Minnie married John Wright, and then stopped the acquaintance after Minnie began to isolate herself from the rest of the town. It is Mrs. Hale who seems to support Minnie from the start, since she is aware of the rough nature of John Wright, and of the hardships that women go through as farm wives.
Contrastingly, Mrs. Peters is the wife of Henry Peters, who is the town's sheriff. She is not knowledgeable about farm life, nor about Minnie. For this reason, she does not pay much attention to the things that Mrs. Hale suggests when she finds the mishandled items at the Wright home. Furthermore, she also refuses to give an opinion stating that Minnie may have done it, because Mrs. Peters has a loyalty to her husband.
MRS. PETERS- Yes, Mrs. Hale?
MRS. HALE- Do you think she did it?
MRS. PETERS- [In a frightened voice.] Oh, I don't know.
MRS. HALE- Well, I don't think she did. Asking for an apron and her little shawl. Worrying about her fruit.
MRS. PETERS- [Starts to speak, glances up, where footsteps are heard in the room above. In a low voice.]
Mr. Peters says it looks bad for her. Mr. Henderson is awful sarcastic in a speech and he'll make fun of her sayin' she didn't wake up.
However, Mrs. Peters slowly changes as she sees the things that Mrs. Hale can identify as either uncommon, or as de-facto evidence. For example, when they find the scattered stitching, Mrs. Peters ignores Mrs. Hale, but we will see how things will remain on the back of her mind.
MRS. HALE- I'll just finish up this end. [Suddenly stopping and leaning forward.] Mrs. Peters?
MRS. PETERS- Yes, Mrs. Hale?
MRS. HALE- What do you suppose she was so nervous about?
MRS. PETERS- Oh -- I don't know. I don't know as she was nervous. I sometimes sew awful queer when I'm just tired. [MRS. HALE starts to say something, looks at MRS. PETERS, then goes on sewing.]
However, when the dead canary is found with its neck wrung, Mrs. Peters suddenly reacts with her own sad experience after a kid killed her kitten. She clearly connects now with Minnie, which means that she has changed: She is a round character now.
MRS. PETERS [In a whisper.] When I was a girl -- my kitten -- there was a boy took a hatchet, and before my eyes -- and before I could get there -- [Covers her face an instant.] If they hadn't held me back I would have -- [Catches herself, looks upstairs where steps are heard, falters weakly] -- hurt him.
MRS. HALE [With a slow look around her.]
I wonder how it would seem never to have had any children around. [Pause.] No, Wright wouldn't like the bird -- a thing that sang. She used to sing. He killed that, too. Well I must get these things wrapped up. They may be through sooner than we think. [Putting apron and other things together.] I wonder where I can find a piece of paper, and string.
Hence, when we see Mrs. Peters taking sides, for the first time, with Minnie's situation, we can certainly see that a change has occured in the character, making it round.