I enter and leave the party hall but Frenni doesn't appear. You should also make the names of the rooms appear somewhere on the screen.
She follows a route from the left party hall > right party hall > bathroom entrance. If she didn't show up, maybe she has already been there.In this part of the game, every time you enter a new room, it's as if some time has passed.
Regarding putting the room name somewhere on the screen, I will keep that in mind.