The War that Saved My Life by Kimberly Brubaker Bradley

Butter refused to ever do anything but walk.
I was nice to him. I tried hard not to smack him, even when his laziness
angered me. I brought him treats, and I brushed him every day, and
sometimes when I rode him I dropped the reins on his neck and just let him
wander around the pasture however he liked. When I stood at the corner gate
and called his name, he came right to me, every time, and he stood without
being tied while I brushed him and put his bridle on. I knew he liked me. He
really did. But he wouldn’t go faster, no matter what. He wouldn’t run, and
until he would run, I knew we’d never be able to jump.
I was afraid Lady Thorton hadn’t meant it when she said I could ask Mr.
Grimes for help, but in the end I decided I had to take the chance.
“I’m going to visit Mr. Grimes,” I said at lunch one day. It was a cold day;
I was glad to be wearing one of Maggie’s old sweaters.
Miss Smith gave me an eye. “How and why?”
“I’ll ride Butter,” I said.
Miss Smith stared.
“I do ride him quite a bit,” I said. “We get on well He’s a very nice pony.
He wouldn’t mind taking me there.”
“Ada,” Miss Smith said, “I may be negligent, but I am not blind. I’m well
aware how much you ride that pony.”
“Yes, miss,” I said.
“I’ve told you and told you to call me Susan,” she said. “Your refusal to do
so is starting to feel like an affront. Why do you want to visit Mr. Grimes?”
“I just want to,” I said. “He was nice to me. Susan,” I added.
She rolled her eyes. “And?” she prompted.
“And I’m having trouble with Butter and I don’t know what I’m doing
wrong. I can’t hardly get him to move. Miss—the iron-face—I mean,
Maggie’s mum—”
“Lady Thorton,” prompted Miss Smith.
“Yeah. Her. She said if I had trouble I could ask Mr. Grimes for help.”