Born sometime during 1998, Tracy was a resident of Ozona, Texas, who was enrolled in an unnamed local school. Other than the fact that she was an only child, not much else is known of her early life.
When a young boy named Nicholas Faye is found murdered, being the second victim of serial killer Jeffrey Charles, the BAU travels to Ozona. Tracy is at first unnamed and she is seen with a group of children consisting of Henry, Matthew, Eric, and Simon. Henry, the oldest, is telling the younger children a ghost story about an old man living in a house on a nearby hill; Simon, Henry's lackey, supports the story's legitimacy. Tracy is frightened by the story and so are Matthew and Eric. It is later revealed that the old man had died prior to the episode when the BAU consider him a suspect in Jeffrey's killings. Tracy is also present at her school when Morgan and JJ are explaining the "buddy system" and the girl sitting next to her asks a question.
Later on, Tracy gets off the school bus and asks Simon to stick to the buddy system and walk home with her. Instead, he goes home with Henry. Jeffrey offers to take her home and Tracy accepts, not knowing that Jeffrey is actually the killer. By the time she was reported missing, Jeffrey had lured her deep in the woods, pretending to take a short-cut. When they reach a playground, Tracy complains and says her feet hurt, that her backpack is too heavy, and that they have been walking too long. Jeffrey takes off her backpack and tries to throw it into the woods, but it only goes a few feet. Then, he attempts to hit Tracy with his baseball bat, but she kicks him and runs off into the woods. Gideon is alerted of her disappearance, and he and the rest of the BAU go into the woods to search for her. Tracy hides behind a tree, but is found by Jeffrey, who takes one last swing at killing Tracy, but misses. She was then rescued when Gideon grabs Jeffrey and stops him from making any further swings. Immediately after this incident, Tracy and her parents moved to McLean, Virginia.
When serial killer Frank Breitkopf starts killing people who were once saved by the BAU, the team starts to frantically search for him. They believe that all possible victims are accounted for, but, after finding the corpse of Rebecca Bryant, the team finds a note that suggests there is another victim. JJ realizes the one person who is not accounted for is Tracy, who had moved to Virginia. When the BAU reaches the Belle residence, Frank had already abducted Tracy. Later on, Gideon receives a phone call from Tracy. Breitkopf had forced her to call Gideon and plea for help. At the end of the episode, after Breitkopf is killed, JJ and Reid find Tracy locked in a walk-in closet, safe. She later calls Gideon again and thanks him for everything; she is then reunited with her parents.