Answer: Emotional stressors like bullying, ostracism and social aggression can certainly cause long-lasting pain. It seems that this primarily occurs, however, only in kids who repeatedly mentally relive the painful event. Unfortunately, it's currently unclear which kids are likely to ruminate on stressful situations and which are not. That said, psychologists have theorized two situations that may make rumination-and thus the experiencing of long-term emotional pain-more likely.
For one, individuals who are already depressed may be more likely to ruminate on emotionally stressful situations. This could occur because depressed people lack the mental strategies we normally use to protect ourselves. As a result, they allow themselves to think repeatedly about a painful situation. In other words, they have no means to stop self-infliction of pain. Unfortunately, their tendency to ruminate may make their depression even worse.
Secondly, kids who repeatedly encounter cues related to the emotional stressor may be more likely to mentally relive the emotionally stressful event(s). For instance, if a tween were bullied every day at lunch, the bleachy smell of the cafeteria may trigger painful memories. The more cues a tween encounters, and the more frequently they're encountered, the more likely the tween is to move into unhealthy stages of coping.
In sum, there's no clear answer as to whether or not your particular child is likely to be overcome by the painful situations she has encountered. That said, considering her tendency toward depressive thoughts and the cues that may be linked to her victimization may enable you to help her cope. For instance, you might seek professional help for her depression and/or work to limit exposure to painful cues, when possible.
Williams, Kipling D., and Nida, Steve A. Ostracism: Consequences and Coping. Current Directions in Psychological Science. 2011. 20(2): 71-75.