These are not bios of the “Nora, this is your life!” variety. Instead, as with the bio you did of your protagonist, it’s story specific. The most important thing to keep in mind as you develop your secondary characters is that each one must be conceived and developed in accordance with the role he or she will play in your protagonist’s story. Thus the first question to ask of each one is Okay, how will this character’s agenda fit into the story I’m going to tell?