It sounds strange but the girls already have a favorite author, Mo Willems. They've enjoyed his series of pigeon books, as have Mike and I, but the one we picked up at the library several weeks ago is a HUGE favorite. The book is Knuffle Bunny Too; A Case of Mistaken Identity. This one happens to feature a preschool aged girl but the protagonist in the original (same title except no "too") is a little boy. Both girls recite a lot of the book and say the author's name once I've read the title aloud. I particularly enjoy the look of the book. The illustrations are drawn over actual photographs. I love that!