Disney trivia is an awesome idea! I would either play Disney scene it and just to all plays over and over and just keep a tally of who guesses first and the winner gets a prize! Maybe do a guessing game of which park they think she will be working at. Have Disney themed treats too! Also make sure there is time for them all to just talk. Oh! Also maybe have like a nice piece of paper or notebook that her friends can write farewell/good luck messages on for her to take with her, or have a paper that they sign all but in the middle so you can take a group picture to put in the middle of it. For the notebook you could do individual photos, to go on the opposite page of the message, like in the Disney autograph books. (you could write photo goes here or do not write on that page) I had a small going away party before I left but it was only a small group of my friends and was a BBQ, it was fun, but I wish my parents would have thrown it for me instead of my friends.