Madison appears as a stereotypical "blonde", physically appealing with archetypical pink and frilly attire. Despite existing in a post-apocalyptic environment, her hair is perpetually in perfect styling and all her clothes and (matching) pink possessions are perfectly clean.
True to her outwardly stereotypical appearance, Madison is a typical airhead, having not even figured out how to turn off the Pinkberry freezer she lived in for an entire decade. However, she does have a great degree of peppy, childlike enthusiasm in everything she does, to the point that she offsets the heavy sarcasm of Tallahassee and Wichita (which she rarely understands). Madison seems naïve, stating that zombies are more afraid of people than people are of them (a line she took from popular movies in a failed attempt to sound clever). Madison is more alert and observant than other characters due to the fact that she is not distracted by any thoughts. In high stress situations this allows her to act quickly and with good judgment, saving the lives of characters seemingly tougher and more capable than she is.
Madison is introduced when Columbus nearly shot her while he was visiting the mall she lived in. She cried out in alarm, claiming that the fur on her jacket was fake and that she was vegan, and they introduced themselves. Madison survived the zombie apocalypse by hiding inside a Pinkberry freezer whenever zombies drew near, and never left the mall in an entire decade until Columbus and Tallahassee found her, the latter of whom Madison mistook for Columbus' dad.
Accompanying them when they left the mall, Madison was brought to their base in the White House. There she asked Columbus for a "tour" until they were alone, then revealing that she really just wanted to have sex with Columbus. At his reluctance, she said she'd been without sex for 10 years and that she would go have sex with Tallahassee if he didn't, at which point he agreed. Afterward, Madison took the Hope Diamond wedding ring Columbus had intended for Wichita, and when Wichita arrived, Madison showed up at the worst time to anger Wichita about Columbus' infidelity. To add insult to injury, she obliviously showed off the ring, saying that anyone who turned down that ring was clearly a fool, which Wichita had done.
When Wichita, Columbus, and Tallahassee prepared to leave in pursuit of Little Rock, Madison accompanied them, Tallahassee leaving her belongings behind. During the trip Madison showed marginally increasing degrees of intelligence, such as when she criticized the cab industry and came up with the concept of ride sharing (which Wichita derided), saved Wichita from a zombie with pepper spray, and even made a sarcastic comment. Madison temporarily left the group during the trip when she ate some trail mix, which she did not know had nuts in them that would aggravate her nut allergy. When the symptoms set in, her companions thought her a zombie and had Columbus "kill" her, but he actually shot over her head and allowed her to live. When her symptoms cleared, she appropriated an ice cream truck because it had an ice box she could hide in, and eventually noticed her old companions on the road. After nearly colliding while she tried to talk while driving, she eventually stopped and rejoined them for the rest of the journey.
Arriving in Babylon, Madison was awkwardly introduced to Little Rock and became visibly distraught when Tallahassee said he would be leaving, although she couldn't even recall his name. She later participated in the barrier to funnel a horde of zombies off the roof of the tower in Babylon to their deaths, and became enamored with Berkeley after Little Rock broke up with him. She remained in Babylon with Berkeley while Little Rock, Columbus, Tallahassee, and Nevada departed.