Dozens of youngsters were quickly organized and led to the front of the stage inside the pitched tent where the authors sat - closer than the public usually gets to first family members.
"We might be in trouble with security, but we're sure they're (the children) safe," said Jenna Bush, who took turns with her mother reading about a boy named Tyrone, who is bored with books until getting caught up in their stories.
The first lady - a former librarian and literacy advocate who helped bring the annual book festival to the National Mall - told the audience the book was inspired by a former student of hers "and all those little boys who would rather do anything than listen to a story."
Jenna Bush, who also has worked as an elementary school teacher, said she was captivated by her mom's classroom stories.
"We were so inspired by Tyrone and other kids like him that we decided we should write about what we know - and I think what we know are kids and books," Jenna Bush said.
After taking children's questions, the first lady and daughter signed books parents and children waiting in a long line. As children shyly stood by the Bushs' table to get their book signed, the mother and daughter asked for their names and if they liked to read. They blew kisses to some youngsters as they rode away in their parents arms.
Popular children's book author and artist Jan Brett was scheduled to be in the same children's pavilion area after the Bushs' book reading. Jennifer Bloom, 42, of Alexandria, Va., said she was upset she and her two children never saw Brett's presentation after waiting in line for hours along with many others.
"Security was not letting anyone in because they were concerned about the Bushes, which is understandable," Bloom said. "The kids didn't get in, we didn't get in. ... It was really a bummer."
More than 70 authors, illustrators, and poets were scheduled to take part in the book festival, which is organized by the Library of Congress.
The festival has grown from about 30,000 attendees in 2001 to more than 120,000 last year.