Children’s author, illustrator, and educator Anna Dewdney, whose toddler-centric picture books starring wildly expressive Baby Llama are multi-million-copy bestsellers, died at her home in Vermont on Saturday, September 3, after a 15-month battle with brain cancer. She was 50.

Dewdney was born December 25, 1965 in New York City. She grew up in nearby Englewood, N.J., and attended high school at Phillips Academy in Andover, Mass. before graduating from the Putney School in Putney, Vt. In 1987, Dewdney received a bachelor’s degree in art from Wesleyan University.

Before she fulfilled her dream of becoming a full-time author and illustrator, she supported herself working as a waitress, a rural mail carrier, and a daycare provider. She also taught art and history to middle-school boys at a boarding school for many years.

Her children’s book career began in earnest with her artwork for The Peppermint Race by Dian Curtis Regan (Henry Holt, 1994). Dewdney went on to illustrate a number of other children’s chapter books in the 1990s. Then, in 2005, Viking published the first picture book she both wrote and illustrated: Llama, Llama Red Pajama. The humorous tale of Baby Llama’s struggles to get to sleep at bedtime received critical praise and became a hit with kids, parents, librarians, teachers, and booksellers. The series now contains more than 10 titles and has sold more than 10 million copies combined. Netflix is producing an animated Llama Llama series that is due out in 2017.

Dewdney did many school, library, and event appearances, where she spoke passionately about her work and children’s literacy. In her role as a literacy advocate, Dewdney wrote a 2013 opinion piece for the Wall Street Journal, emphasizing that “empathy is as important as literacy” when it comes to educating children. “When we read with a child, we are doing so much more than teaching him to read or instilling in her a love of language,” she wrote. “We are doing something that I believe is just as powerful, and it is something that we are losing as a culture: by reading with a child, we are teaching that child to be human. When we open a book, and share our voice and imagination with a child, that child learns to see the world through someone else’s eyes.”

In a release from her publisher, Jen Loja, president of Penguin Young Readers, said, “The entire Penguin Young Readers family is heartbroken. And as we grieve, we also celebrate Anna’s life, in dedicating ourselves to carrying forward her mission of putting books into as many little hands as possible. We will miss her so, but consider ourselves so lucky to be her publishing family and her partner in her legacy.”

Additionally, Ken Wright, v-p and publisher of Viking Children’s Books, shared these thoughts: “Anna was an extraordinary talent. But much more than that, she was a dear, dear friend to so many of us at Viking and Penguin, and she will be deeply and personally missed by her entire Penguin family.”

Dewdney had recently completed a new picture book, Little Excavator, which is scheduled for June 2017 publication from Viking.

She requested that in lieu of a funeral service that people read to a child instead. Dewdney is survived by her partner, Reed Duncan, and two grown daughters.