Etty is a minor character in Code:Realize, and the daughter of Elaine.
A sprite or drawing of Etty is never shown in the game. It is known for sure that she is a child though, and since she is the child of Elaine, it can be assumed that she looks somewhat similar to her.
In the anime, before her mother's death, Etty has long light brown hair tied in two low ponytails, grey eyes, and she wears a yellow dress. After her mother's death, when Cardia returned to the mansion, her hair is now short and she wears a dark blue dress.
Since Etty isn't shown much in the game not much can be told about her personality. She appears to be an average, cheerful, young and well-behaved girl before her mother is killed.
After her mother dies, it can be said she most likely became much more guarded and hard-hearted after the trauma as in most routes, as she never really revises what she said, with the exception of Lupin's route.
Etty appears in all the routes during Chapter 8, Nobody Understands The Truth. When Elaine takes Cardia in. It can be assumed they all had a good and harmonious relationship up until the point where her mother was taken away. When Cardia and Elaine are taken away, she is pretty much forced away and is taken care of by the other villagers until the test to see if Cardia is really a monster ends.
When Cardia returns and gives her the journal, an emotionally distraught Etty calls Cardia a monster and asks why it couldn't have been Cardia instead of her mother. She accepts the book but leaves Cardia there, the weight of what she says on Cardia's mind pretty much for the rest of the story.
In Lupin's route after almost getting killed again when she returns to her mansion, Etty goes to Cardia. She says that she still can't bring herself to completely forgive her but she read the journal her mother left and because her mother seemed to write so many entries about Cardia, and seemed to trust her then that must mean Cardia can't be all bad. Etty takes back what she said to Cardia about calling her a monster, and then runs off not saying much else. After hearing this though, Cardia doesn't hate herself as much as she did before and gains the will to keep living life the way she wants.