Fay had short, brown hair that barely reached her shoulders with messy bangs and dark eyes. She wore a flowing dress, a white scarf, and a coat, along with her respective armband.
Fay did not have much experience with the world at such a young age, needing Grisha to push her out of her comfort zones. She saw the world with whimsy and delight, looking at the airship in the sky in awe.
After leaving their home, Fay and her brother Grisha stared up at the sky and saw an airship, which fascinated them. When the airship flew over their city limits wall, they followed it to the higher end of town, leaving their town without permission. While searching for the airship, Fay and Grisha were hazed by the citizens who saw their armbands and were called the impurities of their region.
At the end of their search for the airship, Fay and Grisha found two Marley officers slacking off on a hill. The men intended to punish Grisha and Fay for trespassing and leaving the internment zone without an exit permit. After offering to take the burden for both of them, one of the men beat up Grisha while the other took Fay away. However Fay was not present when Grisha returned home after his beating.
The next day, Fay's mutilated body was found by the riverbank. The officers who encountered the children met with their parents and told them that Fay was safely left at the border and that it was Fay's own fault for leaving in the first place. Grisha deduced that the men were lying and in no way was Fay's death her own fault. While their mother was overcome with sorrow, their father smiled at the men and told them he would better educate his son on the issue of leaving their town. Later, their father reeducated Grisha on their ancestors' evil past. However, Grisha explained that the Marley men were lying about Fay and when he began to say that he thought they had her killed, his father yelled at him for saying so, Grisha then returned this yelling by saying that he and Fay did nothing wrong.