This book provides parents with some insight on how children come to understand sex and reproduction. Chapter 1 discusses some of the ways children think differently from adults and chapter 2 offers suggestions for talking with children about sex and birth and forming families. In chapters 3-8, children's explanations of the origins of babies are presented according to their six levels of problem-solving ability. Each chapter presents children's ideas about how people get babies, how children's theories of reproduction tie in with their ideas about other of life's puzzles, and how parents can use insight into children's thinking to communicate more effectively with their children. The last three chapters address topics indicative of the changing nature of family life. Chapter 9 addresses the challenge presented to children by the complex concepts of in vitro fertilization, donor insemination, ovum transfer, and surrogacy. Chapter 10 examines the development of children's thinking about adoption: what it means to be adopted, how children understand the motives of adoptive parents and birthparents in making an adoption plan, and children's evolving understanding of the permanence of the family formed by adoption. Chapter 11 explores how children understand the tangle of relationships created by remarriage, when they may have parents and stepparents, siblings and stepsiblings, grandparents and stepgrandparents. (Contains over 80 references.) (TJQ)