In the play Trifles, where are Mrs Hale and Mrs Peters while Mr Hale explains to the county attorney how the murder was discovered? How does their...

The play Trifles starts out in the kitchen of the Wright residence, where the entire party has gathered to try to make sense of what has just taken place. The man of the house, a farmer named John Wright, had just been killed in his sleep, presumably, by his wife, Minnie. Minnie is being held in custody. Meanwhile, witness John Hale, his wife, Sheriff Peters and his wife, and the county attorney, are there looking for clues to the case. 

The setting where the case is looked over is described in a very telling manner:

The kitchen in the now abandoned farmhouse of John Wright, a gloomy kitchen, and left without having been put in order--unwashed pans under the sink, a loaf of bread outside the bread-box, a dish-towel on the table--other signs of incompleted work.

From what we can gather, there is a lot of activity that takes place in the kitchen. It has pots and pans everywhere. People eat there every day. The dishes are also done there. This place seems to be the hover point of the household. Yet, in the case of the Wrights, this very high-traffic area is abandoned and left in chaos. The description is indicative of a similarly chaotic everyday dynamic taking place in there. 

After introducing us to the kitchen area, in comes the Sheriff, Hale, and the country attorney entering from the rear. They all go straight to the stove, for it is cold outside. The wives follow. While the men stick together, and warm up to one another even before going to the stove, the women remain behind, near the door. 

This is telling of the huge division between the two parties.

According to Beverly Smith in her article "Women's Work--Trifles? The Skill and Insights of Playwright Susan Glaspell" published in the International Journal of Women's Studies (March 1982, p. 172-184) this particular part of the scene is very telling

While the men always seem to work in packs, deal with each other in familiar terms, and protect one another, the women stay behind, merely observing. In fact, the women do not acknowledge one another, at first. They just stand silently in the back.

Then, as the men start making sarcastic comments about Minnie Wright's disordered kitchen, and her potential lack of housekeeping skills, the women surprisingly stand next to one another, still silent, and still not quite communicating...yet.

Granted, it will be seen that the women will have the same ability to protect one another and watch each other's backs, however, they do not do it as visibly as males do. It is a question of social behavior, more so than psychology alone. 

Once the two women get to speak, they continue to address one another by their formal, married titles "Mrs. Hale" and "Mrs. Peters". As such, they do not only deductively conclude what actually took place in the house, but they are now doing their best to ensure that the details of the crime--the cues that are all over the house and the men aren't able to discern--never reach the men.  

Still, it is very telling that, within the parameters of formality and social distance, the women are capable of sharing much more insight, and more honest and truthful information, than the men will ever be capable of sharing.