I have a pet one, too. I had five, but I gave the healthy four to a sanctuary friend when they were four and a half months old. I never weighed them, but my biggest two looked about eight pounds, and the smaller two were no more than six pounds I bet. Pretty healthy, probably from free ranging and only getting a cup of grain in the evening spread among the five of them. The one I kept had been the smallest in the first place, then she was bit by a dog and practically skinned, then got fly strike... That is why I kept her. She is much better, but she was really stunted because of this. I named her Foxy because of her spunk. She has terrible depth perception, but she can fly, jump, run, etc. Just a little stupid, but I love her. She was really bony up until like this last week. I can feel that she is getting a bit of, um...padding...on her keel bone, probably from being moved to the same coop as the rest of the flock for the last few months. She is really muscular and lean, though. I have read about people giving them aspirin for their heart.
I do not know the dosage, but I am curious about it. I plan to give her aids for her heart, especially since she has been through a lot of stress, and she will likely not get much exercise this Winter.