Jenna is trying to construct a pedigree for the occurrence of red hair in her family. She has two sisters, one older and one younger, and Jenna is the only one in her family that has red hair. What will be components of Jenna's pedigree?

Based on the scenario being described within the question it can be said that the components of Jenna's pedigree will be a line connecting her mother and father, a colored circle representing Jenna, and two empty circles representing her sisters. Thus representing that the line connects the parents and the three circles are the children of that couple. And the colored in circle represents the child with colored hair.