She picked up her books from the floor as she heard the laughing.
They were laughting at her
But she better than to cause a scene
She was a nobody
And nobodies were not allowed to stand up for themselves
She could feel the pity , guilt and regret in the girl's eyes
The girl that did this to her
The "slut"
After she got up, she continued her way because the recent event just reminded her why being invisible was important.
If they knew you, they were going to judge you.