All three children were in the courtroom. Even though Atticus told them to stay home, and that he did not want them in town that day, and even though Aunt Alexandra told them to stay in their yard. As they entered the courtroom, Scout somehow got separated from Dill and Jem. She knew Jem would come after her so she stayed where she was. When Jem did find her, all the seats were taken and there was standing room only. The courtroom was packed and they didn't think they were going to get a seat. Finally Reverend Sykes brings them in with him, and some of the black people made room for them with in the balcony. The balcony was the only spot that black people were allowed.
Children and women were allowed in the courtroom. When Bob Ewell gets graphic with his words and images, the judge says,
"There has been a request.... that this courtroom be cleared of spectators, or at least of women and children, a request that will be denied for the time being." (pg 174)
Rev. Sykes recommends to Jem that he take Scout out of the courtroom, but Jem insists that she doesn't understand anything anyway --- an argument that Scout silently denies. While the jury is deliberating, Atticus finds out that the children have been there through the whole trial. Jem begs to come back in the evening to hear the verdict. Atticus replies,
"Well, you've heard it all, so you might as well hear the rest. Tell you what, you all can come back when you've eaten your supper......eat slowly, now, you won't miss anything important--- and if the jury's still out, you can wait with us. But I expect it'll be over by the time you get back" (pg 207)
By the time the reader gets to Chapter 22, the trial is over, and Jem is reacting to the verdict. Scout was much younger, and she didn't have the reaction Jem did. Jem doesn't understand how they could have convicted Tom Robinson, and how they could have given him the death penalty. He asks Atticus to explain it. All Atticus can tell him is,
"I dont' know, but they did it. They've done it before and they did it tonight and they'll do it again and when they do it ----seems only the children will weep. (pg 213)