If your client is anything like the spoiled brats on that show, you're in for an adventure!
Seriously, though, these events seem to be less "structured" than a wedding, bar mitzvah, etc. Therefore, I would suggest you communicate with your clients BEFORE the event to learn as much as possible about what they expect from you. Seems like these parties would offer an excellent opportunity for you to pitch your client on doing a "memories" montage for the birthday girl that plays during the party. That's an "add on" service for editing and projection at the event.