The War that Saved My Life by Kimberly Brubaker Bradley

The army had found the suitcase buried in the sand. It contained a radio
transmitter, the sort spies used to send coded messages across the channel.
The perfect Englishman really had been a spy.
I became a hero. The RAF men at the airfield brought me chocolate; the
WVS women pooled together a tablespoon of sugar each, and gave me a
whole bag. Daisy’s mother from the pub hugged me whenever she saw me,
and every time I went into the village I was greeted with smiles and shouts of,
“There’s our little spy-catcher!” or “There’s our good lass!”
It was as if I’d been born in the village. As if I’d been born with two strong
feet. As if I really was someone important, someone loved.
Jamie made me repeat the story over and over again. “Tell me,” he’d beg.
“Tell me your hero story.”
Maggie wrote from her school. Ooh, I wish I’d been with you! I might have
been, you know, if I’d been home.
I wish you had been, I wrote back.
You wouldn’t mind sharing the honors? she replied.
I wouldn’t have minded at all. It would have been easier. Hero wasn’t a
word I was used to hearing. The admiration was interesting, but the attention
made me feel unsettled.
“Say it again,” Jamie said, giggling. “Tell me what you told the first
officer.”
“He looked at my bad foot,” I said, “and I said, ‘my foot’s a long way from
my brain.’”
“And you were right,” Jamie said.
“Yes,” said Susan. “She was.”
Of course, the part that was frightening was that there had been an actual spy.
A real spy. Sent to make the invasion easier. When the air raid sirens started
up again it was hard not to be very afraid.
“But you caught him,” Jamie said.
“I caught one spy,” I said. “One.” The sirens had started earlier than usual