Guillaume Federighi, aka Hey Gee, is a French and American author and illustrator. He began his career in 1998 in Paris, France, and spent time exploring street art and graffiti in several European capitals. Since moving to New York in 2008, he has worked with many brands, developing a reputation in graphic design and illustration for his distinctive style of translating complex ideas into simple and timeless visual stories. He is also the owner and creative director of Hey Gee Studio, a full-service creative agency based in New York.

Evie is 11 years old and loves animals and math. She also enjoys playing with friends, creating stories, playing basketball, watching hockey and playing with her dog, Gus. She lives in Rochester, Minnesota with her parents, her brother and her dog. Evie has been learning to manage her ADHD since she was diagnosed in second grade after her parents noticed that focusing on reading, following directions, finishing tasks and especially remote learning were particularly challenging for her. She is also learning to manage dyslexia.

Angela Mattke, M.D., is a pediatrician in the Division of Community Pediatrics and Adolescent Medicine at Mayo Clinic Children's Center in Rochester, Minnesota. She is medical editor of Mayo Clinic Guide to Raising a Healthy Child. In her daily work, she most enjoys seeing her patients smile and helping families who are struggling with health challenges. Dr. Mattke has a special interest in using social media to connect with patients and families and hosts the podcast Kids Health Matters.