Hi there! You said you associate some songs with Carla. Well this is the song I associate with her. "Born without a heart" by Faouzia. I just feel like the song fits Carla so well, I don't know why.
Okay I just listened to it and yeah it does give me some Carla vibes as well. Maybe the overall somber yet defiant tone of the song? Or the acknowledgement that nurture rather than birth is a bigger factor in a person's sense of empathy and morality? There's a certain sense of regret and a slight hope of becoming better in the future that the song gives off that would fit with her too.