And it hits shelves tomorrow.

Nathan R. Congleton

Jenna Bush Hager and Barbara Pierce Bush first talked about writing a children's book when Jenna was pregnant with her younger daughter, Poppy.

"We were spending a lot of time with Mila [Jenna's firstborn] talking about our sisterhood," says Barbara. "We wanted to make sure that Mila was excited to be a big sister and to have a new playmate and person in her life."

Ultimately, they wrote a memoir for adults instead: Sisters First: Stories from Our Wild and Wonderful Life landed on the New York Times Bestseller list in 2017 and took the Texas-born twins on a cross-country book tour.

Now, two years later, they're back with a book for the younger set, Sisters First.

Like their memoir, Sisters First celebrates the special bond between sisters, but this time, the magic of sisterhood is captured in rhyme and accompanied by whimsical illustrations.

Courtesy of Hachette Book Group

"So much of our life has been so much more imaginative and fun and braver because we had another person next to us, accompanying us through life," says Barbara, who notes that many of the book's fantastical scenarios and crazy concoctions (think mermaids riding alligators and pickles dipped in sprinkles) were inspired by the twins' wild childhood imaginations.

"We wrote the book not just for kids like my daughters, who have blood sisters, but for friends too," adds Jenna. "Sisterhood is such a powerful, all-encompassing feeling of knowing that you have these people, whether they're family, friends, or colleagues, who make you feel like you're enough. That's what my sister has done for me, and it's what I get to witness every day with my girls."

It's also a way for the duo to share their love of reading with the next generation.

"We fell in love with reading because it's in our DNA," says Jenna. "We watched our parents really love to read, and they passed it on to us. And now, I'm hopefully doing the same thing for Mila, Poppy, and Hal."

Sisters First hits shelves November 12. Pre-order the book and find tickets for a book tour date near you here.

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