Hannah is the story of Jacob and Mable Zimmer, who came from Germany in 1900 to achieve a better life in the new country, America. Soon after arrival, Mable died from typhoid fever, leaving Jacob to raise their two girls, Hannah, eleven, and Lilly, eight, by himself.

Jacob was fearful he could not raise two girls alone. He put them in a Catholic Orphanage and was never heard from again. Hannah and Lilly are orphans and live in an unfamiliar Catholic Orphanage. The children are afraid of the nuns and the catholic way of life. The girls have separate rooms but are eventually assigned to a room they can share. They can have the room if they share it with a third person. The other person is a toddler named Samuel.

Hannah and Lilly have no idea how to care for a small child. Hannah and Lilly grow fond of Samuel and are a mother to him. Sam is full of energy and mischief. The three children grow up together and become a family.

Hannah meets David Kilmore. And falls in love and marries him. The couple decides to adopt Sam and his best friend, Duff. They have the family they have always wanted. Life is exciting and adventurous for David and Hannah, trying to raise two orphaned boys. Samis is full of adventure, and Duff is quiet and serious. The two boys are officially adopted on David and Hannah's wedding day.