Side
Disclaimer: I don't own Harry Potter, J.K. Rowling does!
Pansy wasn't dumb. She knew that Lord Voldemort was going to attack the school. And he. He was here. Harry Potter hasn't been in school for at least a year. And even though he was here, she knew why. The battle between good and evil was happening now. And she doesn't know which side she's on.
Pansy guessed she would have to wait and see what would happen next. After all, Slytherin's weren't known to persevere for no reason at all. She would just wait and then see which side she's on.