Sal is visibly having a breakdown of her own during the convenience store holdup; Word of God is that she had no intention of getting away with it and wanted to get caught. That's how thoroughly starved for attention she was.
Ruth: Billie, I am so tired. The school. The alcohol. The stress. The loneliness. I can't survive it forever. I will be worn down. It's just a matter of time. But I can hold out for a little longer. Long enough for you to move on. To stop caring about me so much. Then I can give in. Open a bottle. Maybe slip away. See? That's why I didn't want to tell you, dumbass.
Joyce, who nearly got raped. While she tries to act cheerful, deep down she is still very affected by this event, having nightmares about it and still very scared of meeting the guy again. It also turns out the reason Joyce is rarely alone is because she's too scared to be by herself and follows Walky or Ethan around because she thinks it's safer.