Denise Brennan-Nelson is the author of several children’s titles from Sleeping Bear Press, including Buzzy the Bumblebee, Someday Is Not a Day of the Week, Penny: The Forgotten Coin, Grady the Goose, and the popular series My Teacher Likes to Say; My Momma Likes to Say, and My Grandma Likes to Say. She lives with her husband and daughters in Howell, Michigan.

Rosemarie Brennan teaches writing to middle school and high school students, works in the children's department of her local public library, and does free-lance editing.  Rosemarie also presents writing and creativity workshops to people of all ages around the country. Willow is the first collaboration with her sister, Denise Brennan-Nelson. Rosemarie lives in Brighton, Michigan.