A colorful and fun Introduction to Your New Baby Sister. In hello, Baby Sister! a four-year-old rabbit embarks on the unfamiliar journey of becoming an older sibling in best-selling author-illustrator Martha Day Zschock's Hello! board book series for children. Join the rabbit in discovering how to hold, burp, and change a baby sibling. Along the way, the older sibling learns about sharing an old crib, clothes, toys, and even Mommy and Daddy! The best lesson of all, though, is love. For ages 2-5. 6.4 oz. Author: Martha Zschock. Format: board book. Series: hello.