Abel Reiss was one of the younger daughters of Rod Reiss and his wife, the younger sister of Dirk, Urklyn, and Frieda Reiss, the older sister of Florian Reiss, and the half-sister of Historia Reiss.
Abel was a 12-year-old blonde-haired girl with light, medium length hair that was cut with straight bangs and light eyes. She was only ever seen wearing a plain white robe and a white v-neck dress with a black waistband and white sandals, as was common for girls during any Reiss family gatherings.
In the year 842, Abel was among other Reiss family members, which excluded Florian Reiss, to watch Frieda Reiss devour their uncle, Uri Reiss in the succession ceremony of the First King's power. She watched silently as Frieda's Titan devoured their uncle.
Appearance: Abel was a 12-year-old blonde-haired girl with light, medium length hair that was cut with straight bangs and light eyes. She was only ever seen wearing a plain white robe and a white v-neck dress with a black waistband and white sandals, as was common for girls during any Reiss family gatherings.
History: In the year 842, Abel was among other Reiss family members, which excluded Florian Reiss, to watch Frieda Reiss devour their uncle, Uri Reiss in the succession ceremony of the First King's power. She watched silently as Frieda's Titan devoured their uncle.
Abel Reiss in the story: In the year 845, when Wall Maria fell, Grisha Yeager invaded the Reiss Chapel. Abel was the only member who expressed any excitement or curiosity, only to be held back by Frieda. He then turned into a Titan and killed most of Reiss family members, including Abel Reiss herself.
Trivia: In the Kodansha English translation of Chapter 63, Abel is mistakenly referred to as a male.
Source: Attack on Titan Wiki, available under CC BY-SA 3.0.