Hi Danette,
The classic character meal is Chef Mickey's in the Contemporary. However, given this short notice, you may find that it is fully booked. In fact, many of the character meals may be booked already. My advice is to head over to the
Disney Dining website right now and see what you can find that's still available for character dining. All the character meals offer wonderful tableside interactions with characters.
Given that you have older children, you may find that there are dining experiences that they'd enjoy even more than characters. For example, my teenage children love eating at Disney's gourmet signature restaurants. Artist Point at the Wilderness Lodge and Jiko in the Animal Kingdom Lodge are some of our favorites.
For other ideas, you may want to head over to the independent website DisneyFoodBlog.com. Search there for an article called, "10 Tips for Dining with Teens at Walt Disney World."
Have a great vacation!