Those Shoes by Maribeth Boelts is a book I use to demonstrate empathy to kids. With its attention grabbing illustrations kids won't realize there's a lesson to learn until the a-ha moment.
Jeremy wants the new fashionably cool pair of sneakers but his grandmother just cannot afford them. When they happen upon a pair in a second hand shop Jeremy swears they fit and his grandma buys them. Unfortunately they end up in the back of the closet because they are too small. In a moment of natural empathy Jeremy passes them on to his neighbor Antonio, a kid whose shoes are held together with tape. It's a beautiful moment. This book is an award-worthy story for all.