The War that Saved My Life by Kimberly Brubaker Bradley

I told the whole story, except for the part where Maggie said bad words.
Miss Smith straightened up. Her face looked grim. “So,” she said. “You rode
Jonathan Thorton’s prize hunter double with Miss Margaret, back to her
home?”
“Yes,” I said.
“I don’t believe you,” Miss Smith said.
I didn’t know what to say. I told lies, of course I did. But I wouldn’t lie
about this. I’d been helpful. I’d done a good job, getting Maggie and the horse
home. Grimes had said so. He’d tipped his cap to me, when I got out of the
car.
“I wouldn’t know where she lived,” I said, “if it wasn’t true.”
“Oh, I believe you saw the house,” Miss Smith said bitterly. “I believe
Miss Margaret rode by, and you saw them and followed them. Look at the
state you’re in—foot bleeding again and everything. I believe you saw
Margaret, the horse, and the house. I just don’t believe any of the rest of it.”
My mouth opened, then shut. I didn’t know what to say.
“Go to your room,” Miss Smith said. “Wash yourself off in the bathroom,
then go to your room and stay there. I don’t want to see you again today. I’ll
send Jamie up with some supper once he’s home.”
Hours later Jamie came up with a plate for me. “How was school?” I
asked.
“I hate it,” he said, his eyes dark. “I’m never going back.”
Later still Miss Smith came up with her horrible book. She sat down on the
chair on Jamie’s side of the bed, and she opened the book without looking at
me. I ignored her too. Jamie snugged himself into the blankets. “What
happens next?” he asked, as though the book was something he cared about.
“You’ll see,” Miss Smith said, smiling at him. She opened the book and
started to read.
Next morning at breakfast Jamie said again he wasn’t going back to
school. “Of course you are,” Miss Smith said. “You want to learn to read.
Then you can read Swiss Family Robinson all by yourself.”
Jamie looked up at her through his eyelashes. “I’d rather you read it to
me,” he said sweetly. Miss Smith smiled at him, and the thought ran through
me that I hated them both.