Hattie's New House is likely a children's story, possibly part of the Animal Ark series or a similar animal-focused series by Lucy Daniels. The title suggests the plot revolves around a young animal named Hattie, who is either moving to a new home or is introduced to the main veterinary practice of the series. The narrative would focus on Hattie's adjustment to the new surroundings, any challenges or fears she faces, and the efforts of the human characters to help her settle in. The book is a gentle tale emphasizing empathy, care for animals, and overcoming the anxiety of change.