Minnie Wright's character may not have appeared on stage in Susan Glaspell's playTrifles, but an approximate description of her physical appearance is possible thanks to the information that we get from Mrs. Hale regarding, not only Minnie's life before she marries John Wright, but also regarding the dynamics that take place in the lives of farmers' wives.
The first instance that we get about Minnie does not come from Mrs. Hale, however, but from her husband. When he is asked about what events took place the day before the murder, he makes a mention of John's lack of regard for his wife.
I guess you know about how much he talked himself; but I thought maybe if I went to the house and talked about [getting a party telephone with him] before his wife, though I said to Harry that I didn't know as what his wife wanted made much difference to John..
From this brief statement we can picture a woman in very simple clothes (for she is a farmer's wife and lives in a farm), who may not have much motivation for fancying herself, given that her husband does not even care about her.
We can picture her looking disillusioned, and maybe feeling left out. Yet, we know that, for some reason, that night when Mr. Hale visits the Wrights, Minnie is described as being "kind of done up". Was Minnie trying to impress her husband one last time? Or was she celebrating his death for once and for all?
Mrs. Hale then adds her own information regarding Minnie. She explains to Mrs. Peters that Minnie is a woman who, before marriage, was indeed happier.
[...] she kept so much to herself. She didn't even belong to the Ladies Aid. I suppose she felt she couldn't do her part, and then you don't enjoy things when you feel shabby. She used to wear pretty clothes and be lively, when she was Minnie Foster, one of the town girls singing in the choir. But that -- oh, that was thirty years ago.
Again we see a mention to her feeling of shabbiness. A woman who does not mingle enough with other women is not able to vent female issues, or even trade women's fancies such as dress, looks, or even the social learning of behaviors that women often share. Being that "that was thirty years ago", tells us that Minnie is middle aged, not very well-put together in terms of dress and probably carrying a sad demeanor that reflects her sad situation at home.
We also know that she must have had a constant look of worry and anxiety that reflects in her stitching- an activity that is intended for leisure. Hence, Minnie Wright's worried eyes must have been wide-open at all times.
[...] look at the sewing! All the rest of it has been so nice and even. And look at this! It's all over the place! Why, it looks as if she didn't know what she was about!
Additionally, we can say that Minnie is a beautiful woman but her looks are faded, hiding under a face that is now older, anxious, and depressed.
[..] she was[..] real sweet and pretty, but kind of timid and -- fluttery. How -- she -- did -- change.
Finally, we can conclude that Minnie's beauty and talent is what made her cheerful and sweet. However, since John Wright "killed" all that, Minnie must now look diminutive, fragile, plain, with lost traits of her former beauty, simple and, in her eyes, you would have always seen a look of fear. Perhaps she "did herself up" that night because the monster who took her former beauty and joy is finally gone forever.