They look like crosses to me. The one has good leg feathering, but her tail, body, and face color don't look very cochin-like. It also looks like one has a pea comb, but that may just be the picture.
The chicken world does seem to be very 'buyer beware'. My advise, next time you want to buy a particular breed with the assurance that it conforms to breed guidelines, go to a show. That's how I got my two beautiful bantam brahmas and a rather pretty polish. The gentelman showing the brahmas actually drove in from Nebraska and was happy to part with two of his girls when the show was over. He got gas money, I got two little girls that I can try my had at showing next year.
First I would love to say you have very beautiful chickens
I believe that your cochin is not 100% cochin but, a cross of somekind. I was working on a project which I have since had to give up do to lack of breeding pen space
(long story) But, your baby looks very simalar to what my splits were. I know what they were split with but, I'm not sure yours would be the same.
But, either way they are all beautiful and I'm sure you they get lots of love!!