In the play Trifles there is much conjecture to be made upon the character of Mrs. Wright, on one hand, because she does not take active participation in the play and, on the other hand, because the motive for her crime is also learned by inductive and deductive analysis. The little information that we can gather comes from Mrs. Hale, who used to know the former Minnie Foster since before she had become Minnie Wright, at about twenty years prior.
From the description, we learn that Minnie Foster is your typical country-bound woman who carried on with the traditional activities that take place in remote and isolated places. We know that she "sang beautifully", and was apparently well-known among the other girls for Mrs. Hale seems to have a cherished recollection of Minnie Foster's ribbons, and flowers in her dress. Minnie was apparently also quite active in the community, as she is considered to be lively before her marriage.
From this information the reader can infer that Minnie Foster entered the marriage state automatically and without giving it much thinking. As Mrs. Hale later points out about the women of her society,
(women) all go through the same things--it's all just a different kind of the same thing.
It is safe to conclude that Minnie perhaps became married because, as with other women, any other options to do something else elsewhere were null.
It is said that, shortly after her marriage, Minnie foster adopted the attitude of a battered woman. It was evident in her lack of upkeep in the home, in herself, and even in her stitching. A busy farm wife who is in her right mind would have made her home her primary responsibility, ensuring that all was in place, and that every need within the household is looked after.
Contrastingly, Minnie Foster's state of mind begins to deteriorate, becoming even more evident in the lack of affect of her demeanor, in her abandonment of the "joys of the home", and in what seems to be a daily battle of survival which, with her stitching, she tries her best to tolerate. Now, as the women saw, the stitching's crazy patterns denote an equally disturbed brain; one which can only be ill with the battered-woman syndrome that led Minnie to snap when she could take it no longer.
It is implied in the play that the canary served as Minnie Wrights only companion; that a peddler was selling them "cheap" and that, perhaps, this was the only nice sound that was heard in the home. When John Wright comes that one day and takes the canary out of its house just to wring its neck, Minnie Foster has finally "had it"; it is time for her to take action, but the action that she takes carries with it so much anger that it ends up in death.
After the incident, Minnie is found by Mr. Hale
...rockin' back and forth. She had her apron in her hand and was kind of -- pleating it
She is also described as "queer", "done up", and not quite rational. She merely says to Mr. Hale that her husband is dead, and points at his location. For all we know, Minnie has lost her mind
..she started to laugh, and then she stopped and looked at me -- scared
All of this is evidence of a woman whose spiral into depression as a result of abuse has ended up in a really bad tragedy.