Zeeskite:
It does not sound like this was a yetzer harah issue for her. She was mortified, disappointed, and shocked at the behavior of the boys. This was not a moment of desire for her. She knew unequivocally that this behavior was unbecoming of frum boys and/or girls. Therefore she could have responded with some words of mussar without contradicting the concept you put forth. Of course if this was an issue that she herself struggles with, then ignoring the boys would have been a major victory over her yetzer harah. But this clearly was not the case. (Again I’m not saying she was wrong – I’m saying that had she responded with some sincere words of mussar, she perhaps would not have been wrong either.)