One of the best birthday treats is Ice Cream!!!
Make a ressie for the Ice Cream Social at the Land in Epcot, about 3pm, and tell them it's her 8th Birthday. We have done this several times and on our last visit we were surprised with a Anniversary party with all of the characters. They made us stand up while Mickey & Minnie stood by us while we recited the Disney Wedding Vows (it had something to do with going to WDW all of the time and being good to each other). It's great besides all of the other birthday things you can do there.