Planning for the Winter Break Vacation

My in-laws are what you call 'snow-birds'. After Thanksgiving, they pack up and head off to warm weather aka Florida. We usually visit them during Winter break if dh can take time off from work. Next year, we are planning to see them and also go to Disney World. I'm looking at different websites offering Orlando vacations. My son has not been to any Disney parks yet and I'm sure that he will have a blast. He's also tall enough to be able to ride most of the attractions in the park. My daughter meanwhile thinks she's too old for Disneyworld and prefers Universal Studios.