Take twice as much of everything on the plane-- diapers, wipes, food, bottles, toys as you think you could possibly use! Really, planes get delayed on the runway for much longer than one would think, snacks get spilled and toys tossed aside! Also, take small plastic bags (like from the grocery) for soiled diapers. Be aware that your baby may have some discomfort in the ears at takeoff/landing. Offering a bottle or breastfeeding right after takeoff will probably help her equalize the pressure and be more comfortable.
Have fun. And remember, even if your baby fusses a bit, everyone around you will survive.