Tessie Hutchinson is a well known and fully accepted member of the community. She seems to be on good terms with everybody until her husband Bill draws the slip with the black spot for the Hutchinson family. Then a change takes place in Tessie, and a comparable change takes place in the opinions and attitudes among her assembled friends and neighbors. Even her husband's attitude changes towards her when she starts making an embarrassing scene and threatening to disrupt this age-old community ritual.
Suddenly. Tessie Hutchinson shouted to Mr. Summers. "You didn't give him time enough to take any paper he wanted. I saw you. It wasn't fair!"
"Be a good sport, Tessie." Mrs. Delacroix called, and Mrs. Graves said, "All of us took the same chance."
"Shut up, Tessie," Bill Hutchinson said.
From this point on Mrs. Hutchinson seems like an outsider even in her own community; and when it turns out that she has drawn the black spot, she seems like an outsider even to the members of her family. Little Davie Hutchinson has no idea what is going on, but the two older children are only thinking about themselves.
Mr. Graves opened the slip of paper [for little Davie] and there was a general sigh through the crowd as he held it up and everyone could see that it was blank. Nancy and Bill. Jr.. opened theirs at the same time. and both beamed and laughed. turning around to the crowd and holding their slips of paper above their heads.
Nancy and Bill, Jr. both beam and laugh, although they should realize that their escape narrows the chances down to their mother or father. What is happening to Tessie would presumably happen to any other member of the community if his or her prospects for drawing the black spot increased from one in about three hundred to one in five and then to one in two. Tessie has become a different person under the stress, and her friends and neighbors seem to see and hear a different person. Just as they see her as a different person, she sees all of them as different persons too. They are withdrawing from her while she continues to beg for their attention.
Tessie Hutchinson was in the center of a cleared space by now, and she held her hands out desperately as the villagers moved in on her. "It isn't fair," she said. A stone hit her on the side of the head.
Tessie has finally become a non-person. Nobody cares about her at all. She is just a target. They may wish she would stop making such a racket and just hold still. The narrator doesn't say what her family members are doing, but presumably they are all participating in the stoning--even little Davie, who has been given a few pebbles to throw at his mother.