Jenna Bush Hager and Barbara Bush Interview Each Other: All of the Revelations (Exclusive)

The pair spoke to ET about their new book, 'The Superpower Sisterhood,' and their bond as sisters and what sisterhood means to them.

Jenna Bush Hager and Barbara Bush are showing off one of their superpowers -- interviewing! In ET's exclusive sit-down with the Bush twins, the pair interviewed each other about their new book, The Superpower Sisterhood, discussed their bond as sisters and what a superpower sisterhood means to them.

The Superpower Sisterhood tells the story of Emma, an only child who grows up longing for a sister. Her life is instantly changed when two sets of sisters move to her street and invite her to join their club.

This is the sisters' second children's book together, and while their mother, Laura Bush, is an only child, Barbara said the former First Lady inspired their second story.

"Well, in this new children's book, our main character is named Emma and she's an only child, which might seem unusual for a book on sisterhood, but Emma's based on mom," Barbara explained. "Mom, as you know, was an only child, and she desperately wanted siblings and she never had any blood siblings, but she has the same best friends that she had since she was little in Midland -- still -- and those are her sisters. Those are her chosen sisters."

While none of the children in the book have the traditional Marvel super ability, they each have their own special ability and talent, that grows even strong when they band together.

"In Superpower Sisterhood, that's what happens with Emma," Barbara added. "These other sisters move on her block, and even though they're not her blood sisters, she becomes an honorary sister in their sisterhood club, and all of a sudden their powers can do great things together."

When it comes to their individual superpowers, the Today show co-host shared that her sister Barbara is a whiz at math.

"Your superpower as a kid is that you were incredible at math," Jenna shared. "As you very well know, you won the Dallas City Math Championship."

"Well, I came in 9th, but yes," Barbra interjected, correcting her sister.

"9th in the city is better than not even entering, which was me, but also, more importantly, you had a huge heart and you put that heart into action," Jenna continued.

As far as their superpower as sisters, Barbara said that being together since day one has made them that much more powerful.

"We only know the world together," Barbara shared. "I think we've always been more powerful together, because we've never not had someone walking alongside us. All the scary moments in life when you're little, like, the first day of school or for us, unusual moments like going to the inauguration when we were seven, these intimidating days actually weren't that intimidating 'cause we had someone whose hand we could hold when we were walking in. So, I think we've always been more powerful together."

While they have each other to lean on, the pair also have a few friends and colleagues they consider sisters, like Jenna's co-host Hoda Kotb, Savannah Guthrie and more.

"All of them. All of them," Jenna insisted of her Today show co-workers. "I think it's so lucky to work with a group of incredible women. Savannah and I are such close friends, she’s one of your sissys too, but of course Hoda. I rely on her in so many ways, not just at work, but personally, I constantly am asking advice from her, and I look up to her in so many ways."

Jenna continued, "Sheinelle [Jones] and Dylan [Dreyer] are the best. I just named everybody."

"It's a pretty great crew of superpower sisters," Barbara noted.

"I know," Jenna agreed. "And I tell everybody that if you don't have that superhood... that sisterhood at work, create it. Find the person that you get along with, ask them to get a cup of coffee, because it's so much fun to have this incredible group of sisters to work with."

The Superpower Sisterhood is out now.