I have a orpington that is supposed to be from brown orpingtons. this is the slowest growing bird. it's a pullet and I have 4 birds that I kept from that same hatchdate, 3 orp and one is a wyandotte. this bird is 1/2 the size of the wyandotte (her best bud) and I don't know if this is normal for some mutation colors (although she is a black laced blue) to grow so slowly. she eats well, has been wormed, just is small. I have 2 other lavender orps hatched at the same time and they are larger then the wyandotte. could she be a runt due to her genetic backround?