A young girl and her mother move to an apartment in a new city. Despite her mother's efforts to take her out, the girl would rather play by herself in their cozy home--she feels just fine on her own. Introductions to children her age have her hiding behind her mother's legs, and invitations to group activities have her in tears. That is, until she meets Millie, a rescue dog who is not too big, not too small, and kisses her arm when the girl nervously reaches out. With Millie, saying hello to new people isn't so scary . . . and maybe making a friend isn't either. Through emotionally honest prose and soft, expressive illustrations, Lauren Castillo explores one girl's shyness and anxiety--and how one dog's love helps her open up--in a warm picture book that reminds readers of how the right companion can make the world feel like a less frightening place.