On the following Saturday, Maddie and Peggy spend the afternoon writing a friendly letter to Wanda to tell her she has won the drawing contest. They tell her how pretty her drawings are, and ask how she likes her new school. They consider apologizing for their taunts, but decide that the friendly tone would convey their good intentions. They sign the letter with Xs of love and mail it to Boggins Heights with a request to forward it to the Petronskis' new address. They feel happier after dropping the letter in a mailbox.
Days pass without an answer. Maddie wonders if Wanda was so hurt and angry that she wouldn’t respond. Maddie remembers the peculiar way Wanda walked, with her left shoulder raised. She knew Wanda didn’t have a mother, but had never considered how this meant Wanda herself must have had to wash and iron her one dress every night.
Weeks pass with no response from Wanda. Maddie puts herself to sleep by imagining scenarios in which she defends Wanda from crowds of teasing girls. Maddie would interrupt the taunts to say that Wanda was a girl just like any of them were. Sometimes the scenarios involve Maddie saving Wanda from a sinking ship or the hoofs of a runaway horse.
On the last day of school before the Christmas holidays, Room 13 has a party. After the class acts out the story of Tiny Tim, Miss Mason reveals a letter from Wanda, which she reads aloud. In the letter, Wanda says the class can keep the hundred dresses because Wanda has a hundred new ones in her closet. She requests that the drawing of the green dress go to Peggy and the blue one to Maddie as Christmas presents. Wanda includes an illustration of a large Christmas tree surrounded by tall buildings.
Maddie and Peggy hold their drawings carefully on the way home from school. In the falling darkness, the houses look warmly lit, and the Christmas decorations and bright lights reminded the girls of the colors of Wanda’s hundred dresses.
Peggy holds her drawing under a streetlamp and says the gift must mean Wanda received their letter and forgives them. Maddie is less certain, and feels sad, thinking about how she’ll never see Wanda again and so can never really make things right between them.
At home, Maddie pins up her drawing over a section where her wallpaper has torn. The shabby room is made more lively by the bright drawing. Maddie sits on her bed and looks at the drawing, thinking about how she had stood by and said nothing to defend Wanda, yet Wanda had been kind to her anyway.
Tears blur Maddie’s vision as she studies the drawing intently. The colors are so vivid that Maddie had never noticed how closely the figure’s face and head resembled her. The girl in the drawing had the same short blonde hair, blue eyes, and wide, straight mouth. Wanda had drawn Maddie.
Maddie runs to Peggy’s in excitement. The two lift up the drawing on Peggy’s bed and Maddie points out how the auburn-haired figure in the drawing means that Wanda had drawn Peggy. The girls agree that Wanda must have really liked them.
The book ends with Maddie blinking away tears as she thinks about how Wanda would stand alone against the sunny, ivy-covered wall in the schoolyard and look over at the laughing girls, who never believed Wanda when she said she had a hundred dresses.
In the final chapter, Maddie and Peggy, still remorseful, attempt to reconcile with Wanda by sending her a letter. The act briefly makes Maddie feel better, but her guilt is so strong that she continues to obsess over thoughts of Wanda while waiting for a reply.
It seems as though Wanda is so hurt that she is never going to reply to the letter; Maddie returns to increasingly absurd fantasies in which she rescues Wanda from danger. Maddie is relieved when Miss Mason reads Wanda’s letter to the class. Maddie believes that Wanda must have forgiven her if she decided to single her out in a letter to give her a particular drawing.
On the walk home, the motif of bright colors recurs with vivid images of Christmas decorations reflected in the snow and mirrored in the color palette Wanda chose for her compositions. Peggy is satisfied with the drawing Wanda gave her, but Maddie’s uncertainty returns; she can’t get over the fact that she will be unable to see Wanda in person and make things right between them.
Maddie pins the drawing over a section of torn wallpaper—another signifier of her relative poverty. While staring at the drawing, Maddie realizes that she had been so distracted by the brilliant colors that she never noticed the figure’s face, which resembles her own.
In her excitement, Maddie rushes over to Peggy’s house to point out how Wanda had drawn Peggy as well. This revelation means that Wanda admired them even though they were unkind to her. Wanda did not decide to gift the drawings to the girls in response to their letter, but had intended the drawings for the girls all along.
The book ends with Maddie crying as she recalls the image of Wanda’s social isolation in the schoolyard. Though Wanda had acted as though her being rejected and taunted didn’t affect her, Maddie now understands that Wanda admired the other girls and simply wanted to belong to the group.