In the context of this story, it seems no one else knew about what she's going through, and she herself doesn't know how to handle it yet. She did say she wanted to change, right? She wanted to be like MC. She probably still wanted to be a warrior or maybe that's what expected of her and considering no one probably knew about her trauma, she probably thought it would be shameful to back out at that moment. She also probably really wanted to help, but did not expect things to go that way.
Also, when you're in a situation where your defenses are up due to trauma, your brain tend to freeze as well and it's hard to make the right decisions. That's probably what happened here. Anyway, this was all meant for her to overcome it, so personally I found it interesting and was amused with the growing relationship between these two, especially since MC has been kind of emotionally constipated since the beginning.
I agree with all of this, since it’s in the story lol! But there were a number of comments arguing that Runaan should just die for the sin of having trauma, so my point was okay if we’re saying that she isn’t fit to be a warrior, there are plenty of ways to do that without shaming her for having reasonable reactions to stressful situations. She’s a child soldier and a student, the blame isn’t completely on her.
I completely agree with you
I’m not about to blame a traumatized child for exhibiting symptoms of PTSD, but someone should have noticed what a liability she is and removed her from action. Whether that be the teachers, Raon, or Runaan herself - she should not be out on the battlefield when she cannot handle the sight of gore without risking the lives of her comrades.