Some context that won't help at all: Steven Universe is a show featuring sentient space rocks ("Gems") who project a body around themselves to appear (to human standards) as humanoid women. One of them (Rose Quartz) fucked a man (Greg Universe), which led to the birth of half-human, half-Gem series protagonist Steven Universe. Because of the intricacies involved in cross-species reproduction, Rose Quartz had to give up her life in order to birth Steven, and passed her gem on to him in doing so (the exact details of the process aren't fully explained). This caused tension between Greg and another Gem, Pearl, who had feelings towards Rose Quartz and was less than happy about getting cuckqueaned only to see her beloved die. These tensions were finally resolved come the episode "Mr. Greg". Elated, the ship-happy /sugen/ quickly came up with a hypothetical result of them hooking up romantically: a little half-sister for Steven, whom they named Gretel.
Gretel is a young caucasian girl around 6 to 8 years old. She has medium length dark pink hair with flipped ends, blue eyes, a prominent pointy nose, and a giant pearl embedded in her forehead. Her clothing varies, but she's usually seen wearing shirts or dress shirts with shorts underneath, and normal sneakers or simple open shoes. Her shirt will however always display a star shape.
She's a typical young girl in character. Happy-go-lucky, playful, and with a childlike inquisitive nature and big imagination. She's pacifistic, and has great trouble dealing with the knowledge she's one of very few people who can protect humanity against horrifying Gem monsters, by means of physical combat and containment. She may also have inherited some of her mother's traits, like her orderliness or perfectionism, but this isn't explicitly stated.