I have had her checked out by a vet and there is no known reason for her over eating. Any ideas as to why she does this?? Right now I have to feed her separate so eats only her food and limited amounts. Once the other birds are done eating then she can run loose but that is the only way I can control her eating - I am not sure what else to do.

Or she could be like a New Jersy White Giant and they get big, too.

I had gotten some "Rhode Island Red" pullets and could not figure out why they would lay in the middle of the pan and eat around them and then under them. At 10 wks of age they started have walking problems and breathing problems and found one dead in the run. Had my Aunt to come take a look and she said they were red broilers and they need to be dispatch with in a week or I would find the rest like the dead one or even worse find some with broken legs. Lucky we had green peanuts to boil the following weekend and so we did the job once the peanuts were done.

If you are feeding her by herself you can put her on a "diet."

Good luck

I will continue to keep her on a diet, lol. Right now she goes to her "station" and gets locked in to eat her food while everyone else gets to eat whatever they want. After about 20 minutes eveyone is done, if anything is left in the feeder I take the feeder with me and she comes back out to hang out with the group again. Thanks again! 

MrsKK, Cappy and others may be able to help you ID her breed