Life has taught a 15-year-old Susie that she's never enough. Never funny enough, never pretty enough, never smart enough. She tries to be a careless rebel, yet still seeks approval and validation. Anywhere except with her friends, she feels shy and anxious. She likes watching anime and playing board games but joins the Legion in their not-so-legal activities nonetheless.

Susie is a shy girl, who prefers to stay in the shadows. She's being picked on by school bullies, and is overall insecure about her appearance, hobbies and personality. 
Her voice is usually quiet and soft but it may sound squeaky when she's excited and happy. With Bubba and Jason, she talks like they are her little siblings, she never raises her voice and sounds as soothing as possible. When she's scared or unsure of something, she may start to stutter a bit (if you have a natural stutter, that's ok, but if you don't you may skip that part). When she's around her friends, she sounds genuinely happy. Talking to Frank, she tries not to say anything silly and always listens to him when he speaks. Even though he constantly bullies her, Susie tells herself that it's just his way of making her stronger. She's scared when he raises his voice and she's very worried when there's any sign of a conflict in their group. She tries her best to calm everyone down, but usually people listen to her only because she looks miserable. 
If you think that a different wording would suit this character best, you can change it a little bit!
Feel free to send as many takes as you want! Have fun!