She visits the bathroom

Max got up and left the classroom, Jefferson too occupied by Victoria's sycophantic gawking to pay her any mind, as she put on some music through her headphones.

The school had four bathrooms on each floor. Two for boys, two for girls, though each half of the gendered bathrooms were for littles to use. You can tell because while the girl's bathroom (its door on the right) had the black silhouette of a plain figure wearing a dress, the one to the left had an identical figure, only it was bright pink and had a little bow on its head.

Suddenly Kate, who was upset signified by the quite sobbing sounds she made, ran into the little bathroom, making no mind to Max.