It's Okay to Be Different by Todd Parr
I love the book It's Okay to be Different because it shows the lils just exactly what different is: having no hair, to having different moms and dads, to having a dog as a friend, there's no end to what being different is. The point Parr makes is that it's ok. And sometimes the lil ones need to hear that from a book with pictures that make sense to them.
Here I am reading it. I hope you enjoy it as much as I do.