LI's Idina Menzel and her sister collaborate on children's book

Syosset-raised Tony Award winner Idina Menzel and her younger sister, writer and former teacher Cara Mentzel, have collaborated on a children's book about a little mouse who finds her big and confident voice.

The 48-page picture book "Loud Mouse," illustrated by Jaclyn Sinquett and scheduled for publication Sept. 27 by Disney Books, follows a mouse named Dee who loves singing. When her teacher asks everyone in her class to share something, Dee shares a song — and, according to the publisher's website, learns "that sometimes your best self is big, brave, and yes, loud."

"As I've grown older, I realize that we're doing a disservice to the world when we hide our talents and our gifts," music star Menzel, 50, who shortened her family name of Mentzel for professional reasons, told People magazine. "And when I finally understood that is when I finally found joy in what I was doing and acceptance. So, that was when I called Cara one night and said, 'Now go write a book about that.' "

"[W]e have a job to shine in whatever way we can and not to shy away from that," Mentzel, 47, who wrote the 2017 memoir "Voice Lessons: A Sisters Story," told the magazine. "And that's not a selfish thing, that's not a conceited thing, that's what we're here to do."

"I knew that she would help me interpret whatever it was that I wanted to do because she knows me," said Menzel, who among her other credits voices Elsa of Arendelle in Disney's "Frozen" franchise and sang the Grammy Award-winning song "Let It Go." "She's a great writer, but also a teacher of kids this age," adding that her sister "has an understanding of children's literature from a literacy standpoint [and] from a content standpoint."

"Not everybody is an Idina Menzel, [who] has the issue of being so big … and then wondering how to take up that space with grace," said the younger sibling. "Some people don't know how they shine, or what that is right away, and they're searching for it. So, in a follow-up, we wanted to speak to kids like that. That were more like me."

On social media, Menzel posted that she and her sister "[h]ad the time of our lives creating this story. … It brought us closer and I hope it brings us closer to you and your families as we all search for our biggest brightest selves."