young hen with weak legs. what to do??

We got 5 young hens (we were told they were less than a month from laying - so unsure of exact age) a couple weeks ago and since we brought them home one of the littlest girls has had a hard time with her legs. She can run, jump like normal and up until today able to roost but very shakey and clumsy on her feet. Now, when we picked them up the lady caught one of them by grabbing her leg so im wondering if she caused an injury and being pushed around by my bigger hens hasnt helped. This morning when I went in to water and assess everyones situation "little bird" as we've been calling her was having a much harder time moving about and was limping and somewhat falling over. I have her separated in fear of her being injured further - my hens can be a bit brutal and with the cold weather probably getting a bit sick of their coop. She is thin but eating and drinking no problem - havent had any issues with not eating since we got her and is very social with her original group of birds and loves to be picked up and carried when im in there. Now, do I prepare myself for her having mareks? No symptoms other than weak and wobbly legs or keep her separated and assume thhat her wild ride getting picked up by the leg has caused her issues or a deficiancy of some sort?? Im at a loss for what to do. Very little info out there and what is out there is very general. Any help is very appreciated

 

Thanks for the replies! I will have to stop tomorrow and get them some vitamins and find out what my feed store has for probiotics. I've checked her feet out for bumble foot and I'm not seeing any sores or evidence of anything abnormal. My husband and I flipped her over to check her legs out but we weren't really sure what we were looking for so it didn't do us much good. I've researched a bit about leg injuries and what to look for so will have another look tomorrow and see if anything funky is going on like swelling, possible dislocation or break - I really don't think it's broken but just to be sure. She doesn't appear to be in any pain but She's a rather dramatic little thing and is not impressed about being separated, she tries so hard to hobble about with the other hens. Last time I checked on her she looked rather comfy in her enclose meant and enjoyed her hard boiled egg with molasses and pellets. She even jumped onto the edge Of her little housing unit and roosted for a few minutes ( it's probably about 4 inches wide so easy for her to manage with her legs )