Last year we had a party for her the day we left and we gave her our gift last -- it was an invitation to dinner @ 1900 PF from cinderella (I made the invitation) and it was dated the next day. She freaked out. But, she was turning 8 and had been to Disney a few times, so she knew what was going on. She also understood the concept of dates and realized we were leaving right away. Not all kids are into that.
I don't know if your almost 5 year old will really "get" how great the surprise is, especially since this will be her first trip (how exciting!). Before our first surprise trip we REALLY talked Disney up. ALL THE TIME. Watched the planning DVD a lot, always mentioned how awesome it would be to go to Disney SOMEDAY... and even with that my almost 4 y/o (at the time) was NOT impressed at the surprise. She just wanted to go back to sleep, lol. The video is really funny, she keeps saying she is thirsty and tired while her older sister is jumping around screaming "we're going to Disney!"
