Sosie was choosen as the girl to represent Yukon in the Selection. During the first day, she talked to America about being nervous about her hair, but America told her that her hair was pretty the way it was. Her prep team wanted to change her hair color because they said it would match her skin tone. Sosie ended up dyeing her hair blonde. She was one of the first 8 girls to leave in the first day of the Selection.
Not much is known about Sosie's personality, but during the first book America described her as very nervous and distracted. She was acting like this due to being worried with her prep team wanting to change her hair color, but America told her her hair was already pretty, which made Sosie happy.
Sosie had a wavy long hair, that was described by America as not too light, and also not too dark, but after all, Sosie ended up dyeing her hair blonde.