Amelia had asked Vorian to stay back because she had noticed that Natalia was feeling a little uncomfortable when she had asked her to stay behind. And she had noticed previously that Vorian seemed to be close to David as well as to Natalia. So she thought that Vorian's presence in the room would settle the nerves of Natalia.
Natalia was having a mixture of feeling when she was asked to stay behind in the meeting room. She was feeling a little happy thinking that she might finally get to meet her father. And she was also feeling nervous and a little scared thinking how her father might react to her being here in Celine. She definitely did not want to get scolded or worse, grounded during her term break.
Vorian, on the other hand, was starting to get uncomfortable because he knew what was really coming. And he was prepared to get scolding or even some beatings from Natalia.