If you were me, what would you do?

She's your best friend, if she wanted to see any of her other friends more than she wanted to hang around with you, she would ask one of them to fill out a form. Also she probably wants to re connect with everyone and have fun and feel a part of that place for one last time, so even if she doesn't spend all of her time with you, just remember that's her saying bye to everybody. I also think she's probably just as upset about leaving too and if you are her best friend then she's going to miss you just as much as you are going to miss her. But don't prevent her from saying bye to everyone and having one last fun time with all of you (as a school thing because you will see each other again hopefully) because your going to miss her and you'd rather her spend time with you then anybody else. She will definitely thank you for it at the end.