Why had the compass saved Lizzie's life?

Although Peter’s compass provides literal direction for the family, it is more significant as a symbol of the connection between Peter and the family, and ultimately as a relic of the journey itself. When Peter originally shows Karli the compass, it becomes a bonding point between the two, and it maintains this role throughout the journey, culminating in when Karli displays it as “my big brother Peter’s magic compass” (163). The compass allows the family to put their faith in Peter; however, it is not a symbol of authority so much as a starting point for Peter’s relationship with the family to improve.