Hi Susan!
You have plenty of time to get ready for the Disney World Half Marathon. Especially if you have already started training.
The pace seems intimidating, but a 16 minute-mile pace is really a brisk walk. I don't know if you have this information, but check out the advice from Disney's official trainer,
Jeff Galloway. You can even find a custom training schedule for the Disney World Half. He advocates a run/walk/run method that a lot of runners at Disney will be using (including me). It's a great way to start running, and it has been proven to help keep you injury-free.
Another good thing, is that the pace time will not start until the very last person crosses the starting line. So, even if you start in the last corral, if you place yourself in the front of the corral, you will have a few minutes over that pace requirement.
You will do great, and you have plenty of time, so just relax and have fun with your training! Please let me know if you have any other questions as you prepare.