McScary

Hey so I've been doing the complete pokedex sidequest and I'm stuck on meditite. I read that a girl on the right side of apopphyll academy is supposed to give it to me after I've talked to the four students on the second floor, but the girl isin't there. I remember her being there the first time I got to apopphyll academy, but now she's just gone. Is this a bug or something or am I just missing another requirement for this that I am not aware of?