Hi Lynette!
First, I am sorry to hear that you have been having trouble. There's nothing worse for a runner than putting in all the time training, only to suffer an injury at race time!
No problem, though! There are a large number of walkers in the runDisney races. The rules state that you must stay ahead of a 16/minute mile pace. The sweepers will begin riding at that pace after the very last person crosses that starting line. So, the farther up you are in corral placement, the more time you will have. Even if you are in the last corral, you can place yourself at the very front to gain a little extra time.
There are clocks at every mile marker, but they tell elapsed time since the very first corral started. If you have a phone and/or watch, just keep an eye on your time. You will know what time you will start when you get your corral placement. Each corral's start time will be published in the "official race program" that they give you at the expo, and you can download on the
Princess website. (Click on the RUNNER INFO tab) It will be posted very soon. You can do the math of when you need to hit each mile, based on your corral start time. You could even write it on your arm, so you will know along the way. A lot of people do this with their goal times marked by mile.
I hope this helps! Please let me know if you have any other questions!