What are the motifs in Moon Over Manifest by Clare Vanderpool?

Family is a recurring idea in the story. Jinx has not known a true family because his father ran off when he was a small child and his mother dies, leaving him alone with his Uncle Finn, a con man who only uses Jinx. Ned does not know who his true family is because he was orphaned and brought to Manifest on an orphan train. Like these two boys, Abilene also has never known a home or a true family, but has lived on the rails all her life with her father, Gideon.