One of the characters in "The Common Hours" is Sarah, the daughter of Mary and John Richardson. After Mary leaves her family, Sarah deals with the loss of her mother by drawing pictures of her. Every chapter in the book that tells the story of her mother is introduced with a picture that Sarah has drawn.
The illustrator, Katherine Schmalz, is a mutual aquaintance through the church that she and Tina Stephens attend in Scottsdale, AZ. When Katherine posted artwork on Instagram Tina thought her style was a good match for the book she was writing.