I got 6 RIR on 3/5/18. 5 of them are healthy and big. One was very constipated for several days so I gave her some oil and that seemed to temporarily fix the problem. She’s still having trouble pooping 3 weeks later, but eats and drinks just fine. She is quite a bit smaller than the other RIR. They started pecking her and pulling her feathers on 3/25/18 so I moved her to the bin with chicks 2 weeks younger than her and she is the same size as them. Has anyone ever had this problem before? What should I do? Will she recover and eventually be as big as the other RIR? Does she have something genetically wrong? The picture is her next to a Wyandotte who is 2 weeks younger than her.