When this book’s young, white narrator and her mom move into a new apartment in a new city, she feels comfortable and safe there. She enjoys reading and independent play. But meeting new people? That’s a different story. The thought of a play date with new neighbors or joining the other kids at a local bookstore’s story time make her cry. Then her mom surprises her with a new dog. “A not too big, not too small dog. A just right dog.” Millie sleeps next to the narrator’s bed, “like roommates,” and enjoys three walks a day. Millie’s wagging tail and amiability draw the attention of at least one friendly stranger on every walk. At first, when people wave or stop to pet Millie, the narrator feels too shy to return their greeting. But she feels safe with Millie there, and soon she begins to recognize and even say hello to familiar faces. Gathering her courage for a visit to the dog park, the narrator feels shy when she meets another girl, but looking across the park at Millie romping with new dog friends, she approaches the girl, along with her mom, to say hello. The ink, watercolor, and soft pastel illustrations of this satisfying and believable story astutely depict the narrator’s anxiety via body language that subtly changes as she grows more comfortable around others with the help of her sociable dog. (Ages 3-7)