problems with my kitten

Question
in early September I got a cat for free from a woman on a farm. While I was there I saw this tiny cat who was the sister from the same litter of the cat i chose. The tiny cat had a limp on her front paw,and her eyes were partially matted shut. Well, I left and felt horrible. I ended up going to get the tiny cat. The next day I had to rush her to an emergency vet. She had an eye infection, respiratory infection, ear mites, fleas, and the limp. She did not weigh on the scale. The woman said that both cats were 6 weeks old. however, the tiny cat is a 3rd of the size of her sister. you have to put her directly in front of her food or she wonders around the kitchen looking for it. Litter training has been awful, and she wants to be constantly cuddled and rocked like a newborn. She is more a baby than a cat. Something seems very off, my husband and I are at odds as to what is just not right about her.she just has not developed like her sister, who is your typical independant cat. If you could help, i would be so grateful.


Answer
Without examining her I can not say for sure.  Certainly the fact that she had a URI and parasites could have stunted her growth.  The eye infection may have affected her vision or she may not have had enough of taurine which can affect retinal and brain development.  The limp could just be from an old injury.  

I would recommend confining her to a dog crate for a few weeks until she develops more.  I would recommend supplementing her with some B complex vitamins as well as extra Taurine.  I would also recommend a course of deworming with Panacur to be on the safe side and have a stool sample checked by your vet.