I have 4 hens-2 rhode island reds, 1 delaware and 1 buff orpington. They we're all the same size when I got them as 2 day old chicks and now 5 weeks later the buff is 60% of the size of the others. Shes ok, they're not picking on her or anything but I'm wondering if she will catch up. I heard buffs are large chickens but not this one. Any ideas?