Hi Michele,
Thanks so much for your question. After spending time at Walt Disney World during the first 2 weeks of December this past year, I have to say that it was one of the most magical times I've ever been. The Christmas decorations are so beautiful, and there seemed to be extra pixie dust in the air. It was also a time when the crowds were reasonable.
With 10 days to enjoy the parks, I would say that you and your family have to experience
Mickey's Very Merry Christmas Party at least once during your stay. It's such a fun event, and you'll be able experience the Magic Kingdom with cookies and hot cocoa in hand. Be sure to pull out your camera for Mickey's Once Upon a Christmastime parade, the snow falling on Main Street, and the Holiday Wishes fireworks show. Mickey's Very Merry Christmas Party runs from November to December, so you'll be able to attend if you visit in either month.
Please keep in mind that it will be more crowded around the holidays, like Thanksgiving and Christmas.
I hope this answered your question, Michele. If you have any more questions while planning your vacation, please feel free to ask us at anytime.
Have a fantastical Disney day!