The War that Saved My Life by Kimberly Brubaker Bradley

wants proper birth days. There isn’t a spot for ‘don’t know.’”
“Write down April 5, 1929, for Ada,” Miss Smith said. After asking me
how much I could remember about Jamie being a baby, she’d decided long
ago I must be ten. “For Jamie put February 15.” She looked down at us.
“Nineteen thirty-three,” she said. “We’re pretty sure he’s six years old.”
The man raised an eyebrow, but did as she told him.
“What’s all that mean?” I asked, when we were back out on the street.
“Birthdays are days you get presents,” Jamie said gloomily, “and cake for
tea. And at school you get to wear the birthday hat.”
I remembered Miss Smith asking us about birthdays, when we first came to
her, but I’d never heard about a birthday hat. Turns out it was a school thing.
At Jamie’s school his teacher posted birthdays on a big calendar, and when it
was your birthday you wore a hat and everybody made a fuss over you.
When Jamie’d said he didn’t know his birthday, his class had laughed at
him. He hadn’t told us that.
“But now we have birthdays,” Jamie said contentedly. “What you told the
man. I’ll tell teacher this afternoon and she’ll write it on her calendar.” He
smiled at Miss Smith. “What was it?”
“February 15, 1933,” Miss Smith said.
“It’s not your real birthday,” I said.
“Close enough,” Miss Smith said. “February 15 was my father’s birthday.
Jamie can use it.”
“Is your father dead?”
“No,” Miss Smith said. “At least, not so I’ve heard. I think my brothers
would tell me. It doesn’t matter if Jamie shares. There are only 365 days in
the year, and there are a lot more people in the world than that. Lots of people
have the same birthdays.”
“But it isn’t Jamie’s real birthday,” I said.
“No, it’s not.” Miss Smith turned and bent over so she was looking directly
at me. “When I find out your real birthdays, I’ll change your identity cards.
Okay? Promise.”
“Okay.” I didn’t mind a temporary lie. “How do you find out?”
Miss Smith’s nostrils narrowed. “Your mother knows. When she answers
my letters, she’ll tell us.”