Tillman's picture books focus on the love parents have for their children with animals. Her books On the Night You Were Born, Wherever You Are, My Love Will Find You, The Crown on Your Head, I'd Know You Anywhere, and You're Here for a Reason were New York Times best-sellers.[1][2]
On the Night You Were Born was originally self-published,[3] then re-issued by the imprint Feiwel & Friends,[4] which has published Tillman's subsequent books.